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Parabens and benzophenones are compounds widely used in cosmetics and personal care products. Although human exposure is widespread there is a limited number of epidemiological studies assessing the relationship between exposure to these chemicals and female reproductive health. The aim of the study is to explore the relationship between paraben and benzophenone concentrations and reproductive outcomes among women attending a fertility center. This prospective cohort included 450 women undergoing in vitro treatment (IVF) at fertility clinic in Poland. The validated gas chromatography ion-tap mass spectrometry to assess concentrations of parabens in urine (methyl (MP), ethyl (EP), propyl (PP), butyl paraben (BP)) and benzophenone-3 (BP-3) was used. To explore the relationship between concentrations of examined chemicals and reproductive outcomes (methaphase II (MII) oocyte yield, total oocyte yield, implantation rate, fertilization rate, clinical pregnancy, live births), multivariable generalized linear mixed model was used for the analysis. Increased exposure to butyl paraben was associated with a significant decrease in MII oocyte count (p = 0.007) when exposure to BP was treated as the continuous variable. Additionally, the exposure to BP in the highest quartile of exposure also decreases MII oocyte count (p = 0.02) compared to the lowest quartile. Urinary concentrations of BP were not related to total oocyte count, fertilization and implantation rate, clinical pregnancy, and live birth when the exposure variable was continuous variable or in the quartiles of exposure. Exposure to MP, EP, PP, the sum of examined parabens, and benzophenone-3 were not related to any of the examined reproductive outcomes. Exposure to butyl paraben was associated with a decrease in MII oocyte count among women attending fertility clinic rinsing concerns that exposure may have a potential adverse impact on embryological outcomes. The results emphasize the importance to reduce chemicals in the environment in order to minimize exposure. As this is the first study showing such an association, further research is needed to confirm these novel results in other populations. Graphical Abstract

2-Methoxypropan-1-ol is a by-product of a propylene glycol methyl ether (PGME) manufacturing process, in which it is an impurity at concentrations up to 5%. 2-Methoxypropan-1-ol as a PGME impurity can occur in industry in paints solvents, varnishes, dyes, inks, adhesion agents, ingredients in cleaning formulations and chemical synthesis intermediates. It may also occur as an impurity in cosmetics, although its use in these products is prohibited. At occupational exposure, 2-methoxypropan-1-ol may be absorbed through inhalation and skin. There are no data on the number of people exposed to this compound in Poland and no data on its toxic effects in humans. There is only one study that showed a statistically significant increase in the occurrence of birth defects in children of mothers exposed to 2-methoxypropan-1-ol. The proposed MAC value for 2-methoxypropan-1-ol (20 mg/m3) is based on the systemic toxicity demonstrated in a study on pregnant rabbits (NOAEC value of 1335 mg/m3). Due to its irritant effects, STEL value of 40 mg/m3 and “I” notation are also proposed. There is no basis for establishing a BEI value. Since dermal exposure may contribute significantly to the absorption of 2-methoxypropan-1-ol by workers, a "skin" notation is also required.

Czerwień zasadowa 9 to barwnik używany głównie do barwienia preparatów histologicznych (podstawowy składnik odczynnika Schiffa). Związek ten znajduje się na 25. miejscu Top 50 substancji rakotwórczych na podstawie liczby pracowników narażonych w Polsce, a z danych Centralnego Rejestru o Narażeniu na Substancje, Mieszaniny, Czynniki lub Procesy Technologiczne o Działaniu Rakotwórczym lub Mutagennym wynika, że w 2018 r. narażonych na ten związek było 645 osób (głównie pracowników laboratoriów chemicznych oraz medycznych). W warunkach ekspozycji zawodowej główną drogą narażenia na tę substancję jest układ oddechowy. Za podstawę wyznaczenia wartości najwyższego dopuszczalnego stężenia (NDS) uznano wartość współczynnika nachylenia krzywej dawka–odpowiedź (SF) wyprowadzonego z dwuletnich badań rakotwórczości (narażenie po podaniu substancji z paszą, nowotwory wątroby) na samicach myszy. Przy założonym ryzyku dodatkowego nowotworu 10-4 i uwzględnieniu 40-letniego narażenia zawodowego na ten związek drogą inhalacyjną zaproponowano przyjęcie stężenia 0,02 mg/m3 jako wartości NDS dla czerwieni zasadowej 9. Brak jest natomiast podstaw merytorycznych do ustalenia wartości najwyższego dopuszczalnego stężenia chwilowego (NDSCh) oraz dopuszczalnego stężenia w materiale biologicznym (DSB). Ze względu na brak danych dotyczących wchłaniania czerwieni zasadowej 9 drogą dermalną nie ma również podstaw do oznakowania tej substancji symbolem „skóra”. Natomiast z uwagi na przypuszczalne działanie rakotwórcze na człowieka zaproponowano oznakowanie tej substancji symbolem „Carc. 1B”. Zakres tematyczny artykułu obejmuje zagadnienia zdrowia oraz bezpieczeństwa i higieny pracy będące przedmiotem badań z zakresu nauk o zdrowiu oraz inżynierii środowiska.

Pyrethroids exposure has been associated with adverse reproductive outcome. However, there is no study that explores the effect of environmental exposure and embryological outcomes. This question was addressed in a prospective cohort of couples undergoing fertility treatment. The study aims to assess the association between urinary metabolites of synthetic pyrethroids and embryological outcomes (MII oocyte count, top quality embryo, fertilization and implantation rate). We included 450 women aged 25–45 undergoing assisted reproductive technology (ART) cycle at Infertility Clinic in Poland. Urine samples were collected at the time of fertility procedure(s) to assess four urinary synthetic pyrethroids concentrations (3-phenoxybenzoic acid (3PBA), cis-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane carboxylic acid (cis-DCCA), trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane carboxylic acid (trans-DCCA), cis-2,2-dibromovinyl-2,2-dimethylocyclopropane-1-carboxylic acid (DBCA)) using validated gas chromatography ion-tap mass spectrometry and calculated for each cycle-specific metabolite. To evaluate the effect of environmental exposure to synthetic pyrethroids and embryological outcomes (methaphase II (MII) oocyte yield, top quality embryo, fertilization rate, implantation rate), multivariable generalized linear mixed analyses with random intercepts were prepared. Urinary 3-PBA concentrations decrease MII oocyte count (p = 0.007) in the fourth quartile (>75 percentile) compared to women in the first quartile (≤25 percentile). Additionally, when 3-PBA was treated as continuous variable, the negative association between exposure to pyrethroids and MII oocyte count was also observed (p = 0.012). Exposure to other pyrethroid metabolities (CDCCA, TDCCA, DBCA) was not related to any of the examined embryological outcomes. Exposure to synthetic pyrethroids may be associated with poorer embryological outcome among couples seeking fertility treatments. As this is the first study on this topic, the results need to be confirmed in further studies.

4-Chloro-2-toliloamina (4-COT, 4-chloro-o-toluidyna) i jej chlorowodorek są ciałami stałymi. W warunkach laboratoryjnych 4-COT jest stosowana jako barwnik w immunochemii i w biologii molekularnej. W Polsce narażenie na 4-chloro-2-toliloaminę i/lub jej chlorowodorek zgłaszały wyłącznie laboratoria. Zgłoszona do rejestru liczba narażonych na 4-COT wyniosła 262 osoby w 2012 r., a w 2017 – 12 osób. W warunkach narażenia zawodowego 4-COT wchłania się głównie przez skórę i drogi oddechowe. U osób narażonych stwierdzono działanie methemoglobinotwórcze związku oraz występowanie objawów ze strony dróg moczowych w postaci ostrego, krwotocznego zapalenia pęcherza moczowego. Mediany dawek letalnych 4-COT dla gryzoni (drogą pokarmową) wynoszą 860 ÷ 1 058 mg/kg mc. Związek ten wywiera także umiarkowane działanie drażniące na skórę i oczy. Dane na temat toksyczności podprzewlekłej i przewlekłej 4-COT dla zwierząt wskazują na toksyczność ogólnoustrojową. 4-COT wykazuje działanie mutagennie i genotoksycznie zarówno w warunkach in vivo, jak i in vitro. Powoduje uszkodzenie DNA oraz tworzy addukty z DNA. W dostępnym piśmiennictwie nie ma informacji na temat wpływu 4-COT na rozrodczość ludzi. Nie ma danych na temat embriotoksyczności i teratogenności tego związku. W doświadczeniu na myszach wykazano, że 4-COT nie ma wpływu na potencjał rozrodczy samców oraz rozwój potomstwa. U osób zawodowo narażonych na 4-COT stwierdzano istotny wzrost występowania raka pęcherza moczowego. Brak jest danych o wielkości stężeń 4-COT, na jakie osoby te były narażone. 4-COT jest związkiem rakotwórczym dla zwierząt. 4-COT ma zharmonizowaną klasyfikację jako substancja rakotwórcza kategorii zagrożenia 1B. IARC zaliczyła 4-COT do grupy 2A – związków o prawdopodobnym działaniu rakotwórczym na człowieka. W dostępnym piśmiennictwie nie znaleziono danych dotyczących wydajności i wchłaniania 4-COT różnymi drogami. U zwierząt metabolizm 4-COT może przebiegać szlakami N-acetylacji i N-hydroksylacji/N-oksydacji, przy udziale CYP1A1 i/lub CYP1A2, do aktywnych metabolitów. Związek jest wydalany głównie z moczem w postaci niezmienionej oraz metabolitów, np. kwasu 5-chloroantranilowego i 4-chloro-2-metyloacetanilidu. Nie ma danych na temat toksykokinetyki 4-COT u ludzi. W większości państw nie ustalono wartości dopuszczalnych stężeń dla 4-COT w środowisku pracy ze względu na jej potencjał rakotwórczy. Jedynym krajem europejskim, w którym ustalono wartość normatywu, jest Chorwacja, gdzie wartość NDS ustalono na poziomie 0,01 mg/m3 z jednoczesną notacją „skóra”. Podstawy ustalenia tej wartości nie są znane. Jako podstawę do zaproponowania wartości NDS przyjęto działanie rakotwórcze 4-COT. Wartość NDS wyprowadzono przy wykorzystaniu współczynnika SF = 0,27 (mg/kg-dzień)-1, ustalonego na podstawie występowania nowotworów naczyniowych u myszy. Przy założonym ryzyku R = 10-4 obliczona wartość NDS wynosi 0,02 mg/m3. Nie znaleziono podstaw do ustalenia wartości chwilowej NDSCh i dopuszczalnego stężenia w materiale biologicznym (DSB). Narażenie przez skórę może mieć znaczny udział w ilości związku pobranej przez pracowników, wymagana jest więc notacja „skóra”. Zakres tematyczny artykułu obejmuje zagadnienia zdrowia oraz bezpieczeństwa i higieny środowiska pracy będące przedmiotem badań z zakresu nauk o zdrowiu oraz inżynierii środowiska.

Pentanol to alifatyczny nasycony alkohol monohydroksylowy (C5H11OH), który ma osiem izomerów położeniowych. Cztery z nich są alkoholami I-rzędowymi, trzy – II-rzędowymi, jeden – III rzędowym. W normalnych warunkach pentanole (alkohole amylowe) są bezbarwnymi, łatwopalnymi cieczami, poza 2,2-dimetylopropan-1-olem, który jest krystalicznym ciałem stałym. Pary alkoholi mogą tworzyć mieszaniny wybuchowe z powietrzem. Alkohole pentylowe są stosowane jako rozpuszczalniki: lakierów, żywic, gum, a także w przetwórstwie tworzyw sztucznych i ropy naftowej. Służą również do produkcji syntetycznych środków aromatyzujących oraz jako surowce do produkcji preparatów farmaceutycznych. Główną drogą wchłaniania pentanoli w warunkach narażenia zawodowego są drogi oddechowe. Działają one drażniąco na: układ oddechowy, skórę i oczy zarówno u zwierząt, jak i u ludzi. U ludzi, szczególnie z nietolerancją na niższe alkohole (etanol), izomery pentanolu powodowały podrażnienie skóry. Narażenie zwierząt drogą dermalną przy długotrwałej aplikacji powodowało poważne podrażnienie z rumieniem, atonią, aż do martwicy. W organizmie izomery pentanolu mogą być utleniane lub sprzęgane z kwasem glukuronowym, przy czym alkohole I-rzędowe są metabolizowane głównie do odpowiednich aldehydów, a następnie kwasów, alkohole II-rzędowe są częściowo utleniane do odpowiednich ketonów, a w dużej części glukuronidowane, zaś alkohol III-rzędowy (2-metylo-2-butanol) nie może tworzyć aldehydu i ketonu, dlatego jest wydalany z moczem w niezmienionej postaci jako glukuronid. Mechanizm działania toksycznego pentanoli nie został jednak w pełni wyjaśniony. Na podstawie wyników badań na zwierzętach doświadczalnych wykazano, że krytycznym skutkiem narażenia na pentano-1-ol i jego izomery jest działanie drażniące. Wartość NDS dla pentanoli wyliczono z wartości RD50 wyznaczonej w badaniach na myszach, co daje wartość 75 mg/m3. W celu zabezpieczenia pracowników przed narażeniem na pikowe stężenia pentanoli zaproponowano wartość chwilową (NDSCh) na poziomie dwukrotnej wartości NDS, czyli 150 mg/m3. Nie ma podstaw merytorycznych do ustalenia dla pentano-1-olu i jego izomerów wartości dopuszczalnego stężenia w materiale biologicznym (DSB). Ze względu na działanie drażniące substancję oznakowano literą „I” (substancja o działaniu drażniącym). Zaproponowane wartości normatywów higienicznych powinny zabezpieczyć pracowników przed działaniem drażniącym pentano-1-olu i jego izomerów na oczy i błony śluzowe górnych dróg oddechowych, a z uwagi na to, że skutki układowe obserwowano przy narażeniu na znacznie większe stężenia/dawki, także przed działaniem układowym. Zakres tematyczny artykułu obejmuje zagadnienia zdrowia oraz bezpieczeństwa i higieny środowiska pracy będące przedmiotem badań z zakresu nauk o zdrowiu oraz inżynierii środowiska.

Hexachloronaphthalene (PCN67) is one of the most toxic among polychlorinated naphthalenes. Despite the known high bioaccumulation and persistence of PCN67 in the environment, it is still unclear to what extent exposure to these substances may interfere with normal neuronal physiology and lead to neurotoxicity. Therefore, the primary goal of this study was to assess the effect of PCN67 in neuronal in vitro models. Neuronal death was assessed upon PCN67 treatment using differentiated PC12 cells and primary hippocampal neurons. At 72 h postexposure, cell viability assays showed an IC50 value of 0.35 μg/ml and dose-dependent damage of neurites and concomitant downregulation of neurofilaments L and M. Moreover, we found that younger primary neurons (DIV4) were much more sensitive to PCN67 toxicity than mature cultures (DIV14). Our comprehensive analysis indicated that the application of PCN67 at the IC50 concentration caused necrosis, which was reflected by an increase in LDH release, HMGB1 protein export to the cytosol, nuclear swelling, and loss of homeostatic control of energy balance. The blockage of mitochondrial calcium uniporter partially rescued the cell viability, loss of mitochondrial membrane potential (ΔΨm), and the overproduction of reactive oxygen species, suggesting that the underlying mechanism of neurotoxicity involved mitochondrial calcium accumulation. Increased lipid peroxidation as a consequence of oxidative stress was additionally seen for 0.1 μg/ml of PCN67, while this concentration did not affect ΔΨm and plasma membrane permeability. Our results show for the first time that neuronal mitochondria act as a target for PCN67 and indicate that exposure to this drug may result in neuron loss via mitochondrial-dependent mechanisms.

Cadmium (Cd) is an environmental toxicant and endocrine disruptor in humans and animals, and recent studies have illustrated that the uterus is exceedingly sensitive to Cd toxicity. The aim of the study was to investigate the influence of subchronic (90 days) oral Cd exposure in daily doses of 0.09-4.5 mg/kg b.w. on the balance of sex hormones by estimating estradiol (E2) and progesterone (P) concentrations in the uterus and plasma in comparison with the effects of 17β-E2. Additionally, the uterine weight, histopathological changes in the uterus and ovaries, the regularity of the estrous cycle, Cd bioaccumulation in uterine tissue, and selected biochemical parameters of oxidative stress were determined. A long period of observation (three and six months following the administration period) was used to assess whether the existing effects are reversible. The lowest dose of Cd caused effects similar to 17β-E2: an increase of E2concentration in the uterus, endometrial epithelium thickness, and disturbed estrous cycle with estrus phase prolongation. The obtained results suggest that Cd causes nonlinear response. Higher doses of Cd caused a significant decrease in E2concentration in the uterus and plasma, estrous cycle disturbances, endometrium atrophy, and structural damage in the ovaries. This dose additionally induces lipid peroxidation in the uterine tissues. It is noteworthy that a prolonged time of observation after terminating the exposure showed persistent changes in the concentration of E2in uterine tissue, as well as alterations in estrous cycle phases, and an increase in lipid peroxidation in the uterus. Moreover, significant positive correlations between the plasma E2concentration and endometrial epithelium thickness in all studied groups were found. In summary, subchronic oral Cd exposure of female rats may result in impaired fertility processes.

The World Health Organization points out that the opportunistic pathogen

Ftalan bis(2-etyloheksylu) (DEHP) był powszechnie stosowany w przeszłości, głównie jako plastyfikator. Narażenie zawodowe na DEHP występuje w czasie jego produkcji oraz stosowania, zaś narażenie środowiskowe jest związane z produktami zawierającymi ten związek oraz ze spożywaniem zanieczyszczonej żywności lub wody. Unia Europejska wprowadziła zakaz obrotu produktów zawierających DEHP w stężeniu ≥0,1%. Wchłanianie tego flatalanu może zachodzić drogą pokarmową i inhalacyjną, przechodzi on również przez barierę łożyskową oraz do mleka matki. Dane epidemiologiczne wskazują na związek między narażeniem na DEHP (zarówno zawodowym, jak i środowiskowym) a funkcjonowaniem męskiego układu rozrodczego. Nie wykazano bezpośredniej zależności między narażeniem na DEHP a bezpłodnością. W badaniach na zwierzętach za najczulszy skutek toksyczności przewlekłej tego związku uznano zaburzenia spermatogenezy u szczurów. Jako podstawę do zaproponowania wartości NDS dla ftalanu bis(2-etyloheksylu) przyjęto toksyczne działanie na męski układ rozrodczy obserwowane u szczura (NOAEL = 5,8 mg/kg mc./dzień). Proponuje się przyjęcie wartości NDS dla ftalanu bis(2-etyloheksylu) na poziomie 0,8 mg/m3 . Brak jest podstaw do ustalenia wartości NDSCh oraz DSB. Proponuje się notację „Ft” – substancja działająca szkodliwie na rozrodczość. Z powodu niewielkiego wchłaniania DEHP drogą dermalną brak jest podstaw do przyjęcia notacji „skóra”. Zakres tematyczny artykułu obejmuje zagadnienia zdrowia oraz bezpieczeństwa i higieny środowiska pracy będące przedmiotem badań z zakresu nauk o zdrowiu i inżynierii środowiska.

Cadmium (Cd) is an environmental pollutant known to pose a public health issue. The mechanism of Cd toxicity on the uterus, including the protective role of metallothionein (MT), is still not fully understood. The aim of the study was to evaluate the degree of MT-Cd binding in the uterus of rats exposed per os to Cd at daily doses of 0.09, 0.9, 1.8 and 4.5 mg Cd/kg b.w. for 90 days. To assess the permanence of the bond, the rats were observed over long observation periods: 90 and 180 days after termination of exposure. Additionally, uterine concentration of Zn, Cu, Ca, Mg was determined. Cd leads immediately after exposure to a max. 30-fold increase in the concentration of Cd in the uterus, with only small amounts being bound to MT. After 90 days following termination of exposure, and especially after 180 days, an increase in MT-Cd concentration was noted for the three highest doses; even so, the degree of Cd binding by MT was still small. Additionally, the accumulation of Cd in the uterus disturbs the homeostasis of determined essential elements, manifested by a significant increase in Cu concentration and a decrease in Zn, Mg and Ca, especially 180 days after termination of exposure. The obtained results indicate that MT has only a slight protective role in the uterus and that Cd ions may have harmful effects not related to MT: directly on the uterine tissue, and indirectly by disturbing the homeostasis of its essential elements.

The legacy of polychlorinated naphthalenes (PCNs) manufactured during the last century continues to persist in the environment, food and humans. Metrological advances have improved characterisation of these occurrences, enabling studies on the effects of exposure to focus on congener groups and individual PCNs. Liver and adipose tissue show the highest retention but significant levels of PCNs are also retained by the brain and nervous system. Molecular configuration appears to influence tissue disposition as well as retention, favouring the higher chlorinated (≥ four chlorines) PCNs while most lower chlorinated molecules readily undergo hydroxylation and excretion through the renal system. Exposure to PCNs reportedly provokes a wide spectrum of adverse effects that range from hepatotoxicity, neurotoxicity and immune response suppression along with endocrine disruption leading to reproductive disorders and embryotoxicity. A number of PCNs, particularly hexachloronaphthalene congeners, elicit AhR mediated responses that are similar to, and occur within similar potency ranges as most dioxin-like polychlorinated biphenyls (PCBs) and some chlorinated dibenzo-p-dioxins and furans (PCDD/Fs), suggesting a relationship based on molecular size and configuration between these contaminants. Most toxicological responses generally appear to be associated with higher chlorinated PCNs. The most profound effects such as serious and sometimes fatal liver disease, chloracne, and wasting syndrome resulted either from earlier episodes of occupational exposure in humans or from acute experimental dosing of animals at levels that reflected these exposures. However, since the restriction of manufacture and controls on inadvertent production (during combustion processes), the principal route of human and animal exposure is likely to be dietary intake. Therefore, further investigations should include the effects of chronic lower level intake of higher chlorinated PCN congeners that persist in the human diet and subsequently in human and animal tissues. PCNs in the diet should be evaluated cumulatively with other similarly occurring dioxin-like contaminants.

Among polychlorinated naphthalenes (PCNs), listed by the Stockholm convention as Persistent Organic Pollutants (POPs), hexachloronaphthalenes are considered the most toxic and raise the highest concern. Of these, 1,2,3,5,6,7-hexachloronaphthalanene (PCN67) is considered the main congener affecting human health due to its hepatotoxicity and its ability to disturb the reproductive, endocrine, and hematological systems. It is also prevalent in human serum/plasma, milk, and adipose tissue. However, little is known about its neurotoxicity, despite the fact that anorectic effects have been observed in workers occupationally exposed to PCNs and in animal research on PCN67. Since dopamine is involved in many aspects of food intake, the aim of this study was to confirm whether PCN67 affects dopamine synthesis in differentiated PC12 cells, a widely used model of neurosecretion. Our results show that exposure to PCN67 resulted in diminished dopamine content and release. Moreover, PCN67 also affected the expression of tyrosine hydroxylase and lowered the expression of vesicular monoamine transporter 1 (VMAT1). In addition, significantly lower expression of antioxidant enzymes, including catalase, glutathione peroxidase and copper/zinc superoxide dismutase, was observed in comparison to the vehicle. In conclusion, PCN67 appears to disturb dopaminergic transmission by altering tyrosine hydroxylation, reducing VMAT1 expression and impairing antioxidant protection. Our study provides a potential mechanism for how PCN67 may cause dopamine deficiency and contribute to neuronal death by affecting cellular antioxidant potency; however, this conclusion requires further research.

2,2'-Dichloro-4,4'-methylenedianiline (MOCA) is an aromatic amine. It is produced commercially by the reaction of formaldehyde and 2-chloroaniline. It is not produced in Europe and its import to Europe is estimated at 1000-10000 t/year. MOCA is mainly used as a curing agent in the production of polyurethane elastomers. Occupational exposure to MOCA occurs during production, distribution and use of this compound. In Poland in 2016, 14 people were exposed to this compound, including 10 women. Under occupational exposure conditions, MOCA is mainly absorbed through the skin; absorption in the respiratory tract is of secondary importance. Available literature does not provide data on chronic MOCA poisoning under occupational conditions. No methemoglobinogenic effect typical for aromatic amines was found in exposed subjects. MOCA has a moderate toxic effect on animals; median lethal doses after oral administration to rodents are 400 ÷ 1140 mg/kg of body weight. It also has a moderate irritant effect on the skin and eyes, but no allergenic effect. Data on subchronic and chronic animal toxicity indicate multiorgan toxicity. MOCA shows mutagenic and genotoxic potential, both in vivo and in vitro. In bacterial tests, it requires the presence of metabolic activation. It causes DNA damage and formes DNA adducts both in vitro and in vivo. MOCA also forms adducts with other macromolecules such as haemoglobin, globin or plasma albumin. No data are available on the effects of MOCA on human reproduction or on the embryotoxicity and teratogenicity of this compound. The only rat experiment showed that MOCA has no influence on the reproductive potential of parents and the growth and of pre- and postnatal development of offspring. There are no epidemiological studies in the literature that clearly indicate that occupational exposure to MOCA is the cause of cancer in workers. However, there are reports of bladder cancer, usually found in cystoscopic examination in young men occupationally exposed to MOCA. Animal studies have provided sufficient evidence for the carcinogenic effects of MOCA. It was shown that this compound administered to rats in the diet induces a dose-dependent increase in the number of lung cancer, hepatocellular carcinomas, hemangiosarcomas, mammary gland adenomas and Zymbal gland carcinomas. MOCA administered in capsules to dogs induced tumors of the bladder and urethra. The mechanism of carcinogenic action of MOCA is related to the potential of this compound and/or its metabolites to bind with macromolecules, mainly DNA. MOCA has a harmonised classification as Carc.1B. IARC considered that there was insufficient evidence of MOCA carcinogenicity in humans and that there was sufficient evidence of carcinogenicity in animals. In the overall assessment IARC classified MOCA into group 1 – compound carcinogenic to humans. SCOEL (2010) included MOCA to genotoxic carcinogens with non-threshold effect (group A). MOCA is absorbed into the body by inhalation, ingestion and dermal routes, the latter is the main route of absorption under occupational exposure conditions. There is no quantitative data on efficiency or absorption rate. In animals, regardless of the route of administration, the highest MOCA concentrations are in the liver, lower in the lungs, kidneys, adipose tissue and blood. MOCA is metabolized mainly in the liver by CYP3A4. Metabolism may proceed along the pathways of N-acetylation, N-hydroxylation/N-oxidation and ring hydroxylation. The main and the most reactive and directly carcinogenic metabolite is N-hydroxy-MOCA. MOCA is excreted from the body with urine and faeces. The relative share of these excretion routes in animals depends on both the species and the route of administration. Based on the MOCA measurement in the urine of an employee who accidentally sprayed with molten MOCA, the biological half-life was set at 23 hours. Since the main route of absorption of MOCA in occupational exposure conditions is the dermal route, biological monitoring, usually based on measurement of the total MOCA concentration in urine, is necessary for the assessment of total exposure. Modern monitoring studies have found that although the MOCA concentration in air was low, a significant percentage of urine samples exceeded the detection limit of the method, which for most methods is 0.5 µmol MOCA/mol creatinine. In addition, some studies have shown that the MOCA level in urine correlated with the amount of glove contamination, not the working surfaces. The values of the current hygiene standards in the various countries range from 0.22 mg/m3 to 0.005 mg/m3 and are usually labelled "skin" and "carcinogen". Furthermore, in many countries, no limit values have been set for MOCA due to its carcinogenic effects. Also in the EU, SCOEL did not set a standard value for MOCA. In 2018. The European Commission has proposed to include a limit value of 0.01 mg/m3 as a binding value (BOELV) with the simultaneous notation of 'skin' in Annex III to the proposal for a Directive of the European Parliament and of the Council amending Directive 2004/37/EC on the protection of workers from the risks related to exposure to carcinogens or mutagens at work. At the same time, it was proposed to set the urinary MOCA concentration at 5 µmol MOCA/mol creatinine as the Biological Guidance Value (BGV), in line with the list of recommended values of the Biological Exposure Limits (BEIs) based on the health effects and Biological Guidance Values (BGVs) provided by SCOEL, which however takes the detection limit of the method as the BGV without giving a specific numerical value for this indicator. The basis for proposing a MAC value was the carcinogenic effect of MOCA. Since MOCA is a genotoxic carcinogen with non-threshold effect, the values of hygiene standards should be based on the cancer risk assessment for this compound. All existing risk assessments are based on the results of an experiment on rats receiving MOCA in the diet under chronic exposure conditions. The MAC value currently in force in Poland of 0.02 mg/m3 was derived on the basis of the linear model with the assumed risk of 10-4. The cancer risk assessment using the two-step model gave the risk values accordingly: 4.6 - 10-4 for MOCA concentration 0.02 mg/m3 and 1.7 - 10-4 for 0.01 mg/m3. A similar risk value of 9.65 - 10-5 (≈ 1 - 10-4) for inhalation exposure to 0.01 mg/m3 was assigned by RAC using a linear model. In view of the fact that the risk assessments presented above gave compatible values for 0.01 mg/m3 and that the European Union proposed this value as a binding concentration, it was proposed to use a MOCA concentration in air of 0.01 mg/m3 as the MAC value in Poland. The main route of exposure to MOCA at occupational condition is the dermal route. MOCA levels in workers' urine samples are a better indicator for overall exposure assessment than measuring MOCA concentrations in air. MOCA is not detected in the urine of subjects not occupationally exposed, i.e. it remains below the detection limit of the method. Therefore, the Biological Guidance Value (BGV) for MOCA should correspond to the detection limit of the biomonitoring method. However, for practical reasons, it was proposed to use 5 µmol MOCA/mole creatinine in urine collected at the end of the shift as an equivalent to BEI. Under industrial conditions, total MOCA concentrations below 5 µmol/mol creatinine can be achieved under appropriate hygienic working conditions. Moreover, according to the risk assessment presented by SCOEL, this MOCA concentration in urine leads to a cancer risk of 3 ÷ 4 - 10-6. Biomonitoring should be supplemented by air monitoring and, where appropriate, measurements of dermal contamination, gloves and work surfaces contamination to identify sources of exposure. Since dermal exposure accounts for a significant proportion of the MOCA taken by workers, a 'skin' notation is required. This article discusses the problems of occupational safety and health, which are covered by health sciences and environmental engineering.

Hexachloronaphthalene (HxCN) is one of the most toxic and most bioaccumulative congeners of polychlorinated naphthalenes (PCNs) known to be present in animal and human adipose tissue. Unfortunately, little data is available regarding the negative effect of PCNs on endocrine function. The aim of the study was to investigate the direct influence of subacute (two and four-week) and subchronic (13-week) daily oral exposure of female rats to 30, 100 and 300 μg kg b.w.−1 HxCN on ovarian, thyroid function and neurotransmitters level. The levels of selected sex hormones (progesterone: P and estradiol: E2) in the serum and uterus, regularity of estrous cycle, levels of thyroid hormones (fT3 and fT4), TSH, γ-aminobutyric acid and glutamate levels in selected brain areas and the activity of CYP1A1 and CYP2B in the liver were examined. Estrogenic action (elevated E2 concentration in the uterus and serum) was observed only after subacute exposure, and antiestrogenic activity (decreased E2 level and uterus weight) after 13 weeks administration of 300 μg kg b.w.−1 day−1. Subchronic administration of HxCN significantly lengthens the estrous cycle, by up to almost 50%, and increases the number of irregular cycles. In addition, increased TSH and decreased fT4 serum levels were observed after all doses and durations of exposure to HxCN. Only subacute exposure led to a significant decrease in the level of examined neurotransmitters in all analyzed structures. Additionally, exposure to low doses of HxCN appears to lead to strong induction of CYP1A1 in a liver. It can be hypothesized that HxCN produces effects which are very similar to those caused by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and dioxin-like compounds (DLCs), particularly concerning endocrine and estrous cyclicity disorders. Therefore, HxCN exposure may exert unexpected effects on female fecundity among the general population.

Phenylhydrazine at room temperature is a colorless or yellow oily liquid, at lower temperatures it occurs in a form of a crystalline Phenylhydrazine is used in an organic synthesis as a powerful reducing agent or as an intermediate in synthesis of other chemical compounds, such as dyes and drugs. Phenylhydrazine is also used as a chemical reagent. At the beginning of the 20th century, phenylhydrazine was used as a drug in polycythemia vera and other blood disorders. Occupational exposure to phenylhydrazine and its salts may occur during the production, further processing and distribution of these compounds, and also during their use. In 2014, 711 people were exposed to phenylhydrazine in Poland (including 531 women), of which 2 people only were exposed to phenylhydrazine in the air at a concentration range> 0.1–0.5 of the MAC value (20 mg/m3) . Phenylhydrazine is classified as a toxic substance after oral administration, in contact with skin and after inhalation. The available literature describes several cases of human poisoning with phenylhydrazine with inhalation and through the skin. Adverse effects of phenylhydrazine exposure are progressive hemolytic anemia with hyperbilirubinaemia and urobilinemia, presence of Heinz bodies in red blood cells, impairment of renal and hepatic function as secondary symptom to the haemolytic activity of phenylhydrazine. Methemoglobinemia and leukocytosis sometimes occurred. General symptoms of poisoning included dizziness, diarrhea, general weakness and reduced blood pressure. Phenylhydrazine irritates the skin. Several cases of skin hypersensitivity reactions to phenylhydrazine and its hydrochloride have also been described. It has been shown that phenylhydrazine gives cross-reactions with hydrazine salts. In animals, the main symptoms of acute phenylhydrazine poisoning were the formation of significant amounts of methaemoglobin and its consequences: hemolysis, Heinz bodies formation, reticulocytosis, bone marrow hyperplasia, splenomegaly and liver damage. Motor excitation and tonic-clonic spasms were also observed. As a result of repeated exposure, it was found that phenylhydrazine also causes hemostatic disorders in addition to haemolytic anemia and leads to acute pulmonary thrombosis. The dose-effect relationship cannot be derived from existing data nor the NOAEL value be determined. Phenylhydrazine is an in vitro mutagen and some evidence points to its genotoxic activity in vivo (DNA methylation and fragmentation ). Phenylhydrazine and its salts have been classified as category 2 mutagenic substances. In the available literature and databases, no information was found on the carcinogenic activity of phenylhydrazine and its salts in humans. Carcinogenic activity of phenylhydrazine has been demonstrated in experimental animals. Exposure of mice via oral route resulted in the occurrence of lung tumors and tumors of blood vessels. The International Agency for Research on Cancer (IARC) does not classify phenylhydrazine and its salts as carcinogenic. In the European Union, phenylhydrazine and its salts have been classified as category 1B carcinogens. There is also insufficient data on the effect of phenylhydrazine on reproduction and developmental toxicity, so it is difficult to assess whether these effects may occur in humans exposed to phenylhydrazine and its salts. Based on the observed systemic effects in humans and animals exposed to phenylhydrazine and its salts, it can be assumed that these compounds are absorbed into the body by inhalation, oral route, through the skin and after parenteral administration. There are no quantitative data on the absorption efficiency of individual routes. The main metabolic pathways of phenylhydrazine are hydroxylation to p-hydroxyphenylhydrazine and formation of phenylhydrazones by reaction with natural keto-acids. Metabolites in the form of glucuronides are mainly excreted in the urine. The existing two studies of the carcinogenic activity of phenylhydrazine hydrochloride have shown that the compound administered via the oral route caused a significant increase in the formation of lung tumors or tumors of blood vessels. In the second study, despite the longer exposure time, no significant increase in lung cancer was observed. Although the results of both studies seem to be unreliable in the light of current criteria and are limited to one species (mice) only and one dose, on the basis of them, phenylhydrazine was classified in the EU as a carcinogen category 1B with the assigned phrase H350 - may cause cancer. A quantitative evaluation of phenylhydrazine carcinogenicity was performed using data on the incidence of lung cancer in mice of both genders exposed to phenylhydrazine hydrochloride, administered intragastrically at 1 mg/day. The model adopted for calculations shows that exposure to phenylhydrazine, at the level of the adopted MAC value in Poland (20 mg/m3) over 40 years of work, corresponds to the risk of lung cancer at the level of 5.7 · 10-2. Such risk is unacceptable. From the estimation of cancer risk, it appears that the current value of MAC for substance should be reduced. The existing database on the toxicity of phenylhydrazine and its salts is insufficient to derive a MAC value based on NOAEL/LOAEL values. Due to the mechanism of action and the main toxic effects (haematotoxicity), phenylhydrazine has an aniline-like toxicological profile. It was proposed that the MAC value for phenylhydrazine should be taken analogously to the MAC value for aniline, i.e. 1.9 mg/m3, which corresponds to the risk of lung cancer in occupational exposure conditions of 5.4 · 10-3. Due to the dermal absorption of phenylhydrazine, the "skin" notation has been proposed (absorption through the skin may be as important as in the case of inhalation). Additionally, due to irritating, sensitizing, carcinogenic and mutagenic effects of phenylhydrazine, the normative should be marked with the letters "I" (substance with an irritating effect), "A" (a substance with sensitizing effect), Carc. 1B (carcinogenic substance category 1B) and Muta. 2 (mutagen category 2). There are no evidence to establish the STEL and BEI values.

Pathophysiological changes in the prostate gland—benign prostatic hyperplasia (BPH) and prostatic adenocarcinoma (PCa)—are closely related to the age of men. In the prostate gland, zinc is of particular importance for its proper functioning, especially with regard to the effects of hormonal disorders. The aim of this study was to evaluate zinc, copper and selenium concentrations in different parts of the prostate gland in relation to age and the nature of pathological changes. Zinc and copper were determined by the AAS method and selenium by the spectrofluorometric method. The concentration of zinc in the central part of the prostate increases with age, and in patients over 36 years it is twice as high as in the peripheral part, where no increase in the level of this element was observed with the age of patients. The above data confirm a possible influence of zinc on the formation of PCa (located mostly in the peripheral part of the prostate, with low levels of zinc) and BPH in the central part where the levels of this element are the highest. The results apparently confirm the disturbed homeostasis of zinc and other essential elements in the etiology of BPH and PCa.

Lavandula angustifolia, one of the most popular medicinal plants, is the source of a bioactive essential oil characterized by a wide spectrum of biological activity, e.g., antiseptic, analgesic, and anticancer effects. In dermatology, the oil helps to relieve skin inflammation and exhibit wound healing potential. However, the mechanism of action of the lavender oil depends on its composition, which in turn is dependent on the origin and growing conditions. Our study aimed to compare the composition and proregenerative properties of the commercially-available narrow-leaved lavender oil produced in Provence, France, with the oil obtained from the narrow-leaved lavender cultivated locally in Poland. GC/MS analysis showed that self-manufactured essential oil had lower linalool content than commercial oil (23.2 vs. 40.2%), comparable linalyl acetate content (40.6 vs. 44%), while the proportion of lavandulyl acetate was significantly higher (23.2 vs. 5.5%). To determine the influence of lavender oil on the production of proinflammatory cytokines and proregenerative growth factors, gene expression of the selected signaling molecules by HaCaT cells was investigated using real-time PCR. Results showed a concentration-dependent effect of lavender oils on the production of IL-6, IL-8, and VEGF by the keratinocyte cell line. Finally, the potential of the lavender oil to increase the production of VEGF, the most important angiogenic factor, with the in-house preparation performing significantly better in the in vitro cell models was identified.

Zinc is an essential microelement that plays many important functions in the body. It is crucial for the regulation of cell growth, hormone release, immunological response and reproduction. This review focuses on its importance in the reproductive system of women of reproductive and postmenopausal ages, not including its well described role in pregnancy. Only recently, attention has been drawn to the potential role of zinc in polycystic ovary syndrome (PCOS), dysmenorrhea, or endometriosis. This review is mainly based on 36 randomized, controlled studies on reproductive, pre- and post-menopausal populations of women and on research trying to explain the potential impact of zinc and its supplementation in the etiology of selected female reproductive system disorders. In women with PCOS, zinc supplementation has a positive effect on many parameters, especially those related to insulin resistance and lipid balance. In primary dysmenorrhea, zinc supplementation before and during each menstrual cycle seems to be an important factor reducing the intensity of menstrual pain. On the other hand, little is known of the role of zinc in endometriosis and in postmenopausal women. Therefore, further studies explaining the potential impact of zinc and its supplementation on female reproductive system would be highly advisable and valuable.

Many persistent organic pollutants (POPs) exhibit endocrine disrupting activity but studies on some POPs, e.g., polychlorinated naphthalenes (PCNs), are very scarce. The present study investigates the (anti)estrogenic and (anti)androgenic activities of 1,2,3,5,6,7-hexachloronaphthalane (PCN67) and 1,3,5,8-tetrachloronaphthalene (PCN43) using the yeast estrogen and androgen reporter bioassays. Among the tested substances, antiestrogenic response was only shown by PCN67. The strongest inhibition of estrogenic activity (up to 17.4%) was observed in the low concentration ranges (5 pM - 0.5 nM) in the presence of 1.5 nM 17β-estradiol. Both tested compounds showed partial estrogenic activity with a hormetic-type response. However, both studied chemicals showed strong antiandrogenic effects: their potency in the presence of 100 nM 17β-testosterone for PCN43 (IC50 = 2.59 μM) and PCN67 (IC50 = 3.14 μM) was approximately twice that of the reference antiandrogen flutamide (IC50 = 6.14 μM). It cannot be excluded that exposure to PCNs, together with other endocrine disrupting chemicals (EDCs), may contribute to the deregulation of sex steroid hormone signaling.

Buta-1,3-diene is a gas used in the production of thermoplastic resins, elastomers and synthetic rubber. Buta-1,3-diene is absorbed mainly in the respiratory tract and then metabolized to monoepoxide – 1,2-epoxybut-3-ene and diepoxide – 1.2:3,4 diepoxybutane, and after their conjugation with glutathione is excreted with urine. According to data from the Central Registry on Exposure to Substances, Mixtures, Agents or Carcinogenic or Mutagenic Technological Processes, in 2015 the number of people exposed to buta-1,3-diene in Poland was 958 and additionally about 200 were exposed to petroleum substances which carcinogenic effect is depending on the buta-1,3-diene. According to data from sanitary-epidemiological stations, in Poland in 2013 and 2016, there were no workers exposed to buta-1,3-diene at levels exceeding maximum allowable concentration (MAC) of 4.4 mg/m3. Buta-1,3-diene in small concentrations is a mild narcotic agent for humans, while for occupationally exposed workers it has irritating properties to the mucous membranes of the eyes and airways. Buta-1,3-diene is a substance with low acute toxicity to animals (LC50 value for rats is 270 000 mg/m3). This substance is mutagenic and genotoxic, it can cause damage to the genetic material of somatic and germ cells. It has been proved that buta-1,3-diene is carcinogenic for B6C3F1 mice and rats. There is also epidemiological evidence that occupational exposure to buta-1,3-diene is associated with the risk of a cancer of a lymphohematopoietic system. According to the IARC classification, buta-1,3-diene is included in group 1, i.e., carcinogenic substances for humans, and according to ACGIH classification to group A2, i.e., substances suspected to be carcinogenic for humans. In Europe, buta-1,3-diene is classified in Cat. 1A. carcinogens and Cat. 1B. mutagenic compounds. Buta-1,3-diene does not cause fertility disturbances, and its teratogenic effects appeared when doses were toxic to mothers only. In Directive 2017/2398 of the European Parliament and of Council (EU) 2017/2398 of 12 December 2017 amending Directive 2004/37/EC on the protection of workers from the risks related to exposure to carcinogens or mutagens at work for buta-1,3-diene, binding occupational exposure limit value (BOELV ) was at the level of 2.2 mg/m3 (Official Journal of the EU L 345 of 27/12/2017, p. 87). The directive will be in force in the EU Member States on January 17, 2020. It was proposed to adopt the value of the maximum allowable concentration (MAC) of the buta-1,3-diene at the level of 2.2 mg/m3 and the following values of the biological exposure indices (BEI):  1.6 mg of 1,2-dihydroxy-4-(N-acetyl-cystein-S-yl)butane/g creatinine in urine measured at the end of working shift  2.1 pmol/g Hb - hemoglobin adducts: mixture of N-[1-(hydroxymethyl)prop-2-enyl]valine and N (2-hydroxybut-3-enyl)valine in blood showing exposure for the last 120 days. This standard is additionally marked Carc. 1A – a substance with proven carcinogenic effect for humans and Muta. 1B – a substance that is considered mutagenic for humans. There is no evidence for establishing STEL value for buta-1,3-diene. The estimated additional risk of leukemia during the 40-year exposure to buta-1,3-diene at a concentration of 2.2 mg/m3 is 8×10-7, it is lower than the risk for the general population in Poland, which is 7.15×10-5.

Background: Zinc (Zn) and selenium (Se) play a well-documented role in cancer prevention (e.g., for prostate cancer), and their combined supplementation is often given as a recommended prophylactic agent. The aim of the study was to determine the influence of Zn and/or Se supplementation on the androgen receptor (AR) in the prostate lobes and the serum selected hormone concentrations, a hitherto unresearched topic. Methods: Male rats (n = 84) were administered with Zn and/or Se intragastrically for up to 90 days. The effects of administration on the tested parameters were checked after 30 and 90 days of administration and additionally, 90 days after the end of 90 day administration. Results: Zn alone leads to an increase in serum testosterone concentrations, while the protein expression of AR in both parts of the prostate increases. Combined administration of Zn and Se eliminates the effect of Zn, which may suggest that these two elements act antagonistically. Se supplementation alone results in the same level of AR protein expression in administration and 90 days after administration periods. Conclusion: This paper presents the first report of the influence of Zn and/or Se supplementation on the protein expression of AR in the prostate. Our findings seem to indicate that simultaneous supplementation of both elements may be ineffective.

Cadmium (Cd) is regarded as a potential endocrine disruptor. However, the exact mechanism by which this metal may interfere with the reproductive system has not yet been elucidated. The present study aimed to investigate the effect of subacute Cd oral administration at daily doses of 0.09, 1.8, and 4.5 mgCd/kg b.w. and the impact of Cd on sex hormones (estradiol (E2) and progesterone (P)) in the plasma and uterus, as well as on estrous cyclicity and histopathological changes in uterine and ovary in female rats after terminating the exposure and after a prolonged observation period (3 months). Moreover, Cd bioaccumulation in the uterine and brain tissue of rats was analyzed. The study revealed that oral Cd exposure induced changes in the plasma levels of steroid hormones: decrease in E2 and increase in P after the highest dose of Cd. Probably, for the first time, it was evidenced that circulation sex hormone disturbances in Cd-exposed rats caused irregular estrous cycle, persisting for 3 months after exposure termination; no alterations in these hormone levels in uterine tissue were noted. Cd did not induce estradiol-like hyperplasia of endometrium, but resulted in endometrial edema irrespective of the dose, and caused damage of the ovaries after the highest dose. In summary, subacute oral exposure of female rats to Cd may lead to long-term disturbances in reproductive system.

Ethyl silicate is a colorless liquid with a slightly perceptible odor. This compound finds numerous applications in many industrial branches, e.g., paint and lacquer, chemical (in chemical coatings which has a contact with food), pharmaceutical, semiconductor and in nanotechnology. It is also used as an agent to harden natural stone, terra-cotta, artificial marble, frescoes and clay and in pro-duction of waterproof and acidproof mortar and cements. According to the State Sanitary Inspection data, in Poland in 2007, 2010 and 2013, there were no workers Ortokrzemian tetraetylu. Dokumentacja proponowanych dopuszczalnych wielkości narażenia zawodowego 23 exposed to ethyl silicate at levels exceeding maxi-mum allowable concentration (MAC) of 80 mg/m3. Ethyl silicate is well absorbed via respiratory and alimentary tracts, but its absorption through the skin is rather poor. In workers exposed to ethyl sil-icate, irritating properties to eye and nasal mucosa have been observed. Data on chronic ethyl silicate effects in humans are not available in the literature. In laboratory animals, ethyl silicate acute toxicity expressed in median lethal doses is relatively low. Ethyl silicate shows a mild irritating effect on rab-bit’s eyes, it does not cause dermal irritation or al-lergic effects. There are no data on ethyl silicate chronic toxicity. Short-term and subchronic studies performed on mice and rats exposed to ethyl sili-cate through inhalation and after its administration in other ways showed except for necrotic lesions in the olfactory epithelium of nasal cavity (in mice), changes in the liver (in rats) and kidneys. The latter comprised interstitial inflammation and necrotic lesions in renal tubules. Short-term exposure of rats to high ethyl silicate concentrations induced its toxic effect also on lungs. Ethyl silicate mutagenic effect has not been re-vealed in Ames tests. On the basis of few data, it has been proved that this compound did not cause reproductive and developmental toxicity. This compound has not been categorized by the Inter-national Agency for Research on Cancer (IARC) with respect to its potential carcinogenic risk. The presented evidence shows that the major toxic effect of ethyl silicate at high concentrations (over 2000 mg/m3) is eye and nasal mucosa irritation in humans, whereas the nephrotoxic effect and dam-age to the olfactory epithelium of nasal cavity are observed in laboratory animals. On the basis of the nephrotoxic effect of ethyl sili-cate, its maximum allowable concentration (MAC) was calculated. The results of two independent in-halation experiments in mice were used to deter-mine NOAEL value. Inhalation exposure of mice to ethyl silicate at concentration of 430 mg/m3 (50 ppm) for 90 days or 2 and 4 weeks did not cause nephrotoxic effects. This compound at higher con-centrations caused nephrotoxicity. Exposure to concentration of 760 mg/m3 (88 ppm) caused sig-nificant decrease in kidney weight, and after expo-sure to concentration of 865 mg/m3 (100 ppm) in 20% of animals interstitial inflammation of kidney tubules have been observed. The authors of the documentation proposed to adopt a concentration of 430 mg/m3 as NOAEC value of ethyl silicate for the nephrotoxic effects observed in mice. After adopting relevant uncertainty coefficients (total value, 8) the calculated MAC value for ethyl silicate is 54 mg/m3. Taking into consideration the fact that in 2008 SCOEL proposed a concentration of 44 mg/m3 as 8-h TWA for ethyl silicate, which was based on the same effects (nephrotoxicity) and NOAEC value adopted from the same experiments, it was pro-posed to assume a concentration of 44 mg/m3 as MAC value of ethyl silicate. This substance is in-cluded in the directive establishing the IV list of in-dicative occupational exposure limit values with-out establishing a short-term STEL value. The proposed MAC value for ethyl silicate should protect workers against systemic effect and poten-tial irritating effect. There are no reasons for adopt-ing STEL and BEI values for this compound.

Nitroethane is a colorless oily liquid with a mild fruity odor. It is used mainly as a pro-pellant (e.g., fuel for rockets), and as a solvent or dissolvent agent for cellulose esters, resins (vinyl and alkyd) and waxes, and also in chemical synthesis.Occupational exposure to nitroethane may occur during the process of its production and processing. There are no data on air concentra-tions of nitroethane in occupational exposure. In 2010–2015, workers in Poland were not exposed to nitroethane concentrations exceed-ing the maximum allowable value – 75 mg/m3 (the limit value valid since 2010).Nitroethane can be absorbed into the body via inhalation of its vapors or by ingestion.The discussed cases of nitroethane acute poi-soning caused by an accidental ingestion of artificial fingernail remover containing pure nitroethane concerned children under three years. Few hours after ingestion, cyanosis and sporadic vomiting were observed in children. The methemoglobin level reached 40÷50%.Neither data on chronic nitroethane poisoning in humans nor data obtained from epidemio-logical studies are available.On the basis of the results of acute toxicity studies nitroethane has been categorized in the group of hazardous compounds. However, eye and dermal irritation or allergic effects have not been evidenced. The studies of sub-chronic (4 and 90 days) and chronic (2 years) exposure to nitroethane per-formed on rats and mice (concentration range 310 ÷ 12 400 mg/m3) revealed the methemo-globinogenic effect of this compound and a minor damage to liver, spleen, salivary gland and nasal turbinates.Niroethane has shown neither mutagenic nor carcinogenic effects. Its influence on fertility has not been evidenced either. After chronic exposure (2 years) of rats to ni-troethane at concentration of 525 mg/m3 (the lowest observed adverse effect level – LOAEL), a slight change in a body mass of exposed fe-male animals and subtle changes in biochemi-cal parameters were observed, but there were no anomalies in hematological and histopatho-logical examinations.The value of 62 mg/m3 has been suggested to be adopted as the MAC value for nitroethane after applying the LOAEL value of 525 mg/m3 and relevant coefficients of uncertainty. The STEL value for nitroethane was proposed ac-cording to the methodology for determining short term exposure level value for irritating substances as three times MAC value (186 mg/m3) to prevent the effects of sensory irri-tations in humans. Because of its methemoglo-binogenic effect, 2% Met-Hb has been suggest-ed to be adopted as the value of biological ex-posure index (BEI), like the value already adopted for all methemoglobinogenic sub-stances.The Scientific Committee on Occupational Exposure Limits (SCOEL) proposed the time-weighted average (TWA) for nitroethane (8 h) as 62 mg/m3 (20 ppm), short-term exposure limit (STEL, 15 min) as 312 mg/m3 (100 ppm) and “skin” notation.Proposed OEL and STEL values for nitroethane were subjected to public consultation, con-ducted in 2011 by contact points, during which Poland did not raise any objections to the pro-posals. The proposed values for nitroethane by SCOEL has been adopted by the Advisory Committee on Safety and Health at Work UE (ACSH) and included in the draft directive establishing the IV list of indicative occupa-tional exposure limit values.

The crystal structure of the new polymorphic form of 3-aminoflavone (3-AF) has been determined by single crystal X-ray diffraction. This report presents results of fluorimetric studies on 3-AF in methanol and aquatic solvents. Based on 3D fluorescence emission spectra, optimal values for excitation (&lambda, ex) and emission/analytical (&lambda, em) wavelength, the analytical concentration range as well as the range of concentration quenching for the studied compound were established. Moreover, the limit of detection (LOD) and the limit of quantification (LOQ) were determined. The results were compared with those obtained using the standard UV-Vis absorption spectrophotometric method. The effect of acidity (pH) and the concentration of halide anions (chlorides, bromides, iodides and fluorides) on fluorescence quenching were analysed.

Although Persistent Organic Pollutants (POPs) are some of the most dangerous environmental toxicants, data on their impact on hemostasis are virtually limited. 1,2,3,5,6,7-hexachloronaphthalene (PCN67) seems to be one of the most toxic congeners of polychlorinated naphthalenes (PCNs), which have recently been listed as POPs. The toxic effects of PCNs are similar to other chlorinated aromatics, e.g. polychlorinated dibenzo-p-dioxins (PCDDs), so an impact on hemostasis could not be excluded. Therefore, this study examines, for the first time, if short-term (two and four weeks) exposure of a mixture of hexachloronaphthalene congeners with a PCN67 as a predominant component to female Wistar rats may have an impact on selected hemostasis parameters, such as overall potential and kinetic parameters of clot formation and fibrinolysis; hematology and basic coagulology parameters. It also examines the influence of PCN67 on the stability of erythrocyte membranes. Obtained results indicate that PCN67 may be an important disturbing factor regarding both coagulation and fibrinolysis processes, as well as platelet count. Exposure to PCN67 significantly affected clot formation and lysis processes and diminished fibrinogen concentration after both administration periods. After two weeks of administration, an increased activated partial thromboplastin time (APTT) was noted; after four weeks - decreased platelet count with concomitant increased in mean platelet volume. Moreover, PCN67 may exert adverse effects on the red blood cells membrane stability, which were manifested by a statistically significant increase of red blood cells lysis.

Introduction Colorectal cancer is one of the most common cancers worldwide. Incidence rates of large intestine cancer indicate a role of environmental and occupational factors. The role of essential elements and their interaction with toxic metals can contribute to the explanation of a complex mechanism by which large intestine cancer develops. Bearing this in mind, determining the levels of essential and toxic elements in tissues (organs), as well as in body fluids, seems to shed light on their role in the mode of action in malignant disease. Aim Determination of the levels of cadmium, zinc, copper, selenium, calcium, magnesium, and iron in large intestine malignant tissue. Material and methods Two intraoperative intestine sections were investigated: one from the malignant tissue and the other one from the normal tissue, collected from each person with diagnosed large intestine cancer. Cadmium, zinc, copper, calcium, magnesium, and iron levels were determined with atomic absorption spectrometry, and selenium levels by spectrofluorimetric method. Results The levels of copper, selenium, and magnesium were higher in the malignant than in normal tissues. In addition, the zinc/copper and calcium/magnesium relationship was altered in malignant tissue, where correlations were lower compared to non-malignant tissue. Conclusions The results seems to demonstrate disturbed homeostasis of some essential elements. However, it is hard to confirm their involvement in the aetiology of colorectal cancer.

Hexachloronaphthalene (HxCN) is one of the most toxic congeners of polychlorinated naphthalenes (PCNs). This study assesses the prenatal toxicity of HxCN after daily administration at doses of 0.1-1.0mg/kg b.w. to pregnant Wistar rats during organogenesis. We evaluated also the expression of CYP1A1 mRNA and protein in the livers of dams and fetuses, as well as the placenta. The results indicate that 0.3mg/kg b.w. was the lowest HxCN toxic dose for dams (LOAEL) while a dose of 0.1mg/kg b.w. was sufficient to impair the intrauterine development of embryos/fetuses without maternal toxicity. Regardless of the applied dose, HxCN generated embryotoxic effects. Dose-dependent fetotoxic effects were associated with HxCN exposure. HxCN was found to be a strong inducer of maternal and fetal CYP1A1. Expression of CYP1A1 mRNA in the placenta appears to be the most sensitive marker of HxCN exposure.

Objectives Due to structural and toxicological similarities to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), polychlorinated naphthalenes (PCNs) were included in the Stockholm Convention on Persistent Organic Pollutants (POPs) in 2015. Hexachloronaphthalene (HxCN) is considered to be one of the most toxic congeners of PCNs. The objective of this study was to determine the maternal and fetal tissue concentrations of hexachloronaphthalene after a single administration. Material and methods Pregnant female Outbred Wistar rats were used for the study. The [14C]-HxCN was administered in a single oral dose of 0.3 mg/rat (150 kBq/rat) on gestational day 17 (GD17), GD18 or GD19. All dams were sacrificed on GD20. The blood and selected tissue samples taken from mothers and fetuses 24 h, 48 h or 72 h after exposure were evaluated for the distribution of HxCN. Results Maximum concentrations of HxCN in pregnant rats were found in the liver and adipose tissue. Relatively high levels of HxCN were also reported in the spleen, ovaries, adrenal glands and uterus, as well as in the sciatic nerve, brain and kidneys. Hexachloronaphthalene penetrates through the blood-brain barrier (BBB), as evidenced by twice the concentration in the brain compared to the blood concentration, and through the placental barrier, as indicated by the level of maternal-fetal compartment (placenta, amniotic fluid, litter). Among the examined fetal tissues, the highest levels of HxCN were found in the kidneys and in the brain. The concentrations in these organs were higher than that found in the maternal blood. Conclusions This paper is the first to detail the concentrations of HxCN in the maternal tissues and the transplacental transfer of the tested compound to the fetuses. The exposure of pregnant rats to HxCN results in its accumulation in the maternal liver, fat tissue, reproductive and nervous system, and particularly in the fetal brain. This demonstrates both the effective absorption and significant systemic accumulation which could lead to negative health implications. Int J Occup Med Environ Health 2018;31(5):685-695.