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Volcanogenic air pollution studies and their effects on the respiratory system are still outnumbered by studies regarding the effects of anthropogenic air pollution, representing an unknown risk to human population inhabiting volcanic areas worldwide (either eruptive or non-eruptive areas).This study was carried out in the Azorean archipelago of Portugal, in areas with active non-eruptive volcanism. The hydrothermal emissions within the volcanic complex of Furnas (São Miguel Island) are responsible for the emission of nearly 1000 tons of CO2 per day, along with H2S, the radioactive gas –radon, among others. Besides the gaseous emissions, metals (e.g., Hg, Cd, Al, Ni) and particulate matter are also released into the environment. We test the hypothesis whether chronic exposure to hydrothermal emissions causes pulmonary oxidative stress, using Mus musculus as a surrogate species. M. musculus were live-captured in: two villages with hydrothermal emissions and one village without any type of volcanic activity. Immunohistochemical evaluations were performed to access the level of pulmonary oxidative stress using an OxyIHCTM Oxidative stress detection kit, and the detection of terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end-labeling (TUNEL) was used to evaluate apoptosis in lung tissues. Mice chronically exposed to hydrothermal emissions presented increased levels of oxidative stress and amount of apoptotic cells. We demonstrate, for the first time, the high oxidative stress potential in the lungs of mice chronically exposed to hydrothermal emissions. This study also highlights the Mus musculus as a useful bioindicator for future biomonitoring programs in these types of volcanic environments.

Neuroinflammation is a process related to the onset of neurodegenerative diseases; one of the hallmarks of this process is microglial reactivation and the secretion by these cells of proinflammatory cytokines such as TNFα. Numerous studies report the relationship between neuroinflammatory processes and exposure to anthropogenic air pollutants, but few refer to natural pollutants. Volcanoes are highly inhabited natural sources of environmental pollution that induce changes in the nervous system, such as reactive astrogliosis or the blood-brain barrier breakdown in exposed individuals; however, no neuroinflammatory event has been yet defined. To this purpose, we studied resting microglia, reactive microglia, and TNFα production in the brains of mice chronically exposed to an active volcanic environment on the island of São Miguel (Azores, Portugal). For the first time, we demonstrate a proliferation of microglial cells and an increase in reactive microglia, as well an increase in TNFα secretion, in the central nervous system of individuals exposed to volcanogenic pollutants. This research was supported by the Universidad de Alicante VIGROB-186.

Volcanoes are a natural source of gaseous elemental mercury (GEM) (Hg0). Monitoring GEM releases of volcanic origin has been widely studied; however, few studies have been performed about the biomonitoring of species exposed to GEM, rendering an unknown risk to the worldwide populations living in the vicinity of an active volcano. In this pilot study, we used Mus musculus as a bioindicator species to understand to what extent lungs are the main route of mercury uptake in populations chronically exposed to active volcanic environments. Autometallographic silver protocol was used to detect mercury deposits in the histological lung slides. Abundant mercury deposits were found in the lungs of specimens captured at the site with volcanic activity (Furnas Village, S. Miguel Island—Azores). The presence of mercury in the lungs could represent not only hazardous effects to the lung itself but also to other tissues and organs, such as brain and kidneys. This study confirms that the main uptake route for GEM is the lungs and that, even at very low concentrations in the environment, a chronic exposure to Hg0 results in its bioaccumulation in the lung tissue. These results reinforce that biomonitoring studies should be combined with monitoring classical approaches in order to better characterize the risks of exposure to Hg0 in volcanic environments. Ricardo Camarinho is currently supported by a PhD fellowship grant (M3.1.a/F/048/2015) from Fundo Regional da Ciência (Regional Government of the Azores). info:eu-repo/semantics/publishedVersion

The health effects of mercury vapor exposure on the brain in volcanic areas have not been previously addressed in the literature. However, 10% of the worldwide population inhabits in the vicinity of an active volcano, which are natural sources of elemental mercury emission. To evaluate the presence of mercury compounds in the brain after chronic exposure to volcanogenic mercury vapor, a histochemical study, using autometallographic silver, was carried out to compare the brain of mice chronically exposed to an active volcanic environment (Furnas village, Azores, Portugal) with those not exposed (Rabo de Peixe village, Azores, Portugal). Results demonstrated several mercury deposits in blood vessels, white matter and some cells of the hippocampus in the brain of chronically exposed mice. Our results highlight that chronic exposure to an active volcanic environment results in brain mercury accumulation, raising an alert regarding potential human health risks. These findings support the hypothesis that mercury exposure can be a risk factor in causing neurodegenerative diseases in the inhabitants of volcanically active areas. info:eu-repo/semantics/publishedVersion

Air pollutants (either of natural or anthropogenic origin) represent a considerable environmental risk to human health by affecting the respiratory system and causing respiratory disorders. In this study, we investigate the effects of chronic exposure to hydrothermal emissions on the nasal cavity of mice since it is the first and the most exposed region of the respiratory system. This study, carried in S. Miguel Island, Azores—Portugal, used Mus musculus as a bioindicator species. Mice were captured in an area with non-eruptive active volcanism (Furnas Village) and another area without volcanism (Rabo de Peixe, reference site). The hydrothermal emissions present at Furnas Village are characterized by the continuous release of several gases (CO₂, H₂S, ²²²Rn) along with metals (e.g. Hg, Cd, Zn, Al) and particulate matter into the environment. We test the hypothesis whether chronic exposure to this specific type of pollution causes epithelial morphometric, mucosecretory and neuronal alterations on the nasal cavity. Thickness measurements were taken in the squamous, respiratory and olfactory epithelia. The relative density of cell types (basal, support and neurons) was also assessed in the olfactory epithelium and the mucosecretory activity was determined in the lateral nasal glands, Bowman’s gland and goblet cells. Mice chronically exposed to hydrothermal emissions presented thinner olfactory epithelia and lesser mucous production, which could result in loss of olfactory capabilities as well as a decrease in the protective function provided by the mucous to the lower respiratory tract. For the first time, it is demonstrated that, in mice, this specific type of non-eruptive active volcanism causes epithelial and mucosecretory alterations, leading to the loss of olfactory capabilities. Ricardo Camarinho is currently supported by a Ph.D. fellowship grant (M3.1.a/F/048/2015) from Fundo Regional da Ciencia (Regional Government of the Azores). info:eu-repo/semantics/publishedVersion

Mercury accumulation has been proposed as a toxic factor that causes neurodegenerative diseases. However, the hazardous health effects of gaseous elemental mercury exposure on the spinal cord in volcanic areas have not been reported previously in the literature. To evaluate the presence of volcanogenic inorganic mercury in the spinal cord, a study was carried out in São Miguel island (Azores, Portugal) by comparing the spinal cord of mice exposed chronically to an active volcanic environment (Furnas village) with individuals not exposed (Rabo de Peixe village), through the autometallographic silver enhancement histochemical method. Moreover, a morphometric and quantification analysis of the axons was carried out. Results exhibited mercury deposits at the lumbar level of the spinal cord in the specimens captured at the site with volcanic activity (Furnas village). A decrease in axon calibre and axonal atrophy was also observed in these specimens. Given that these are relevant hallmarks in the neurodegenerative pathologies, our results highlight the importance of the surveillance of the health of populations chronically exposed to active volcanic environments. This research was supported by the University of Alicante VIGROB-186. info:eu-repo/semantics/publishedVersion

Recent studies have shown that exposure to hydrothermal emissions has a negative impact on the respiratory system. Still, volcanogenic air pollution studies are still outnumbered when compared to anthropogenic studies which can result in an unknown risk to the human populations living near volcanically active areas. This study was carried out in São Miguel Island, with noneruptive volcanically active environments, such as the Furnas volcano caldera. Its noneruptive volcanism presents itself as hydrothermal emissions, mainly by the release of nearly 1000 T d-1 of CO₂ along with H₂S, and the radioactive gas radon; metals [e.g., mercury (Hg), cadmium (Cd), copper (Cu), and zinc (Zn)] and particulate matter are also released in a daily basis. We test the hypothesis whether chronic exposure to hydrothermal emissions causes pulmonary oxidative stress, using Mus musculus as a surrogate species. Mus musculus was live-captured in two villages with hydrothermal emissions and one village without any type of volcanic activity. The level of pulmonary oxidative stress was immunohistochemically assessed by using an OxyIHCTM Oxidative stress detection kit, and the detection of terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end-labeling (TUNEL) was used to evaluate apoptosis in lung tissues. Mice chronically exposed to hydrothermal emissions presented increased levels of oxidative stress and amount of apoptotic cells. We demonstrate, for the first time, the high oxidative stress potential in the lungs of mice chronically exposed to hydrothermal emissions. This study highlights the usefulness of M. musculus as a bioindicator species and enforces the necessity of regularly biomonitor the inhabitants of hydrothermal areas to prevent respiratory pathologies. Ricardo Camarinho is currently supported by a PhD fellowship grant (M3.1.a/F/048/2015) from Fundo Regional da Ciencia (Regional Government of the Azores). info:eu-repo/semantics/publishedVersion

Volcanogenic air pollution studies and their effects on the respiratory system are still outnumbered by studies regarding the effects of anthropogenic air pollution, representing an unknown risk to human population inhabiting volcanic areas worldwide (either eruptive or non-eruptive areas). This study was carried in the archipelago of the Azores- Portugal, in two areas with active volcanism (Village of Furnas and Village of Ribeira Quente) and a reference site (Rabo de Peixe). The hydrothermal volcanism of Furnas volcanic complex is responsible for the release of 1000 t d−1 of CO2, H2S, the radioactive gas – radon, among others. Besides the gaseous emissions, particulate matter and metals (Hg, Cd, Zn, Al, Ni, etc.) are also released into the environment. We tested a hypothesis whether chronic exposure to volcanogenic air pollution causes lung structural remodelling, in the house mouse, Mus musculus, as a bioindicator species. Histopathological evaluations were performed to assess the amount of macrophages, mononuclear leukocyte infiltrate, pulmonary emphysema, and the production of pro-inflammatory cytokine TNF-α. Also, the percentage of collagen and elastin fibers was calculated. Mice chronically exposed to volcanogenic air pollution presented an increased score in the histopathological evaluations for the amount of macrophages, mononuclear leukocyte infiltrate, pulmonary emphysema and production of TNF-α; and also increased percentages of collagen and elastin. For the first time, we demonstrate that non-eruptive active volcanism has a high potential to cause lung structural remodelling. This study also highlights the Mus musculus as a useful bioindicator for future biomonitoring programs in these type of volcanic environments.

We have evaluated buccal epithelial cell micronucleus formation as a biomarker of genotoxic damage following occupational exposure to low doses of ionizing radiation. Buccal epithelial cells were collected from 42 occupationally exposed medical personnel and 39 non-exposed individuals (reference group). Each individual in the exposed group was routinely monitored with a personal radiation badge. The frequency of micronucleated cells (MNC) was significantly higher in the exposed group (5.26 vs. 1.33 MNC/2000 cells) and correlated strongly with accumulated radiation dose (Annual Deep Dose, mSv). Occupational exposure to low doses of ionizing radiation was associated with an 80% relative increase in the frequency of MNC (MRR = 1.8; 95% CI: 1.1–2.8), suggesting that such exposures cause DNA damage. This non-invasive biomonitoring method should be generally applicable to studies of workers who are exposed occupationally to low doses of IR.

Recent studies have shown that exposure to hydrothermal emissions has a negative impact on the respiratory system. Still, volcanogenic air pollution studies are still outnumbered when compared to anthropogenic studies which can result in an unknown risk to the human populations living near volcanically active areas. This study was carried out in São Miguel Island, with noneruptive volcanically active environments, such as the Furnas volcano caldera. Its noneruptive volcanism presents itself as hydrothermal emissions, mainly by the release of nearly 1000 T d

Tree-ring inter-annual pattern variation is crucial in dendrochronology, allowing the identification of possible limiting factors on growth. Thus, trees exposed to subtropical or tropical climates without a marked seasonality may show a low degree of interannual variation, impeding a straightforward dendroclimatological approach. Meanwhile, subtropical regions, and areas in transitional climates such as the Azores archipelago, are widely unexplored in terms of dendroclimatology, providing opportunities to work with endemic trees, including the dominant Azorean tree Juniperus brevifolia (Seub.) Antoine. To evaluate the dendrochronological potential of J. brevifolia, we analyzed tree-ring patterns, crossdating capabilities, and correlation with climate parameters. We sampled 48 individual trees from two natural populations (Sao Miguel and Terceira islands) using an increment borer. Besides, a Trephor tool was used to obtain wood microcores for micro-anatomical analysis. Although the transition between early and latewood was evident, partially indistinct ring boundaries and wedging rings were present in some cases, affecting the crossdating process, but not impeding the establishment of reliable ring-width chronologies. Following detrending, master chronologies were built and correlated with monthly temperature and precipitation data using the treeclim R package. The climate-growth relationships indicated negative correlations with late summer temperature in both populations. Considering our results and the importance of J. brevifolia as a dominant tree in the Azores natural forests, we conclude that it shows an acceptable potential for dendrochronological research. Thus, this study provides baseline information to help fill the knowledge gap regarding the climate-growth relationship of Azorean trees.

Fluoride is often found in elevated concentrations in volcanic areas due to the release of magmatic fluorine as hydrogen fluorine through volcanic degassing. The exposure to high levels of fluoride can affect the processes of bone formation and resorption causing skeletal fluorosis, a pathology that can easily be mistaken for other skeletal diseases. In this study, we aimed to determine if fluoride concentration in the femoral bone of wild populations of the house mouse ( Mus musculus ) is a good biomarker of exposure to active volcanic environments naturally enriched in fluoride, allowing their use in biomonitoring programs. The fluoride concentration of the whole femoral bone of 9 mice from Furnas (5 males and 4 females) and 33 mice from Rabo de Peixe (16 males and 17 females) was measured by the potentiometric method with a fluoride ion selective electrode. Fluoride in bones was significantly higher in the mice from Furnas when compared with the mice from Rabo de Peixe (616.5 ± 129.3 μg F/g vs. 253.8 ± 10.5 μg F/g). Accumulation rates were also significantly higher in the mice collected in Furnas when compared with Rabo de Peixe individuals (3.84 ± 0.52 μg F/day vs. 1.22 ± 0.06 μg F/day). The results demonstrate a significant association between exposure to fluoride in the active volcanic environment and fluoride content in bone, revealing that bone fluoride concentration is a suitable biomarker of chronic environmental exposure to fluoride.

Klossiella is a genus of apicomplexan coccidian parasites with a global distribution, whose members typically infect the renal tissue of a wide variety of vertebrate hosts with a high level of host specificity. The presence of this parasite has been previously associated with kidney inflammatory processes. To our knowledge, this is the first report on the prevalence of Klossiella muris in the house mouse (Mus musculus) in Portugal (São Miguel Island – Azores). The prevalence of K. muris was determined through histopathological examination of renal tissue collected during necropsy of 130 mice captured between the years of 2011–2019. K. muris was diagnosed in 45.38% (CI95: 40.9–85.4) of the examined mice. Infection with this parasite was associated with mild to severe kidney inflammation, assessed by the presence of inflammatory processes in the renal cortex and medulla. Capsule First record on coccidiosis caused by infection of Klossiella muris in Mus musculus in Portugal. Ricardo Camarinho is currently supported by a PhD fellowship grant (M3.1.a/F/048/2015) from Fundo Regional da Ciência (Regional Government of the Azores). info:eu-repo/semantics/publishedVersion

As in many archipelagos, the Azorean primary forest was largely cleared and replaced by secondary forest and grassland, the Azorean tree Laurus azorica (Seub.) Franco being one of the dominant trees in the remaining natural forests. Dendrochronological and dendrometric studies in the Azores mainly focused on non-indigenous trees, either used for timber (e.g., Cryptomeria japonica D. Don) or considered as invasive (Pittosporum undulatum Vent.). Therefore, this study aims to describe the growth ring anatomy of L. azorica, and to understand the relationship between dendrometric traits (e.g., trunk diameter at breast height, tree height), and the number of growth rings. Growth ring anatomy was accessed by wood anatomical preparation of microcore samples while tree age estimation was based on growth ring counts in wood cores taken at breast height and at base. A total of 145 trees were sampled, resulting in 262 increment cores, at six representative stands of laurel forest in S&atilde, o Miguel Island (Azores). The wood anatomical analysis confirmed the presence of clear annual ring boundaries, and a high structural similarity towards Laurus novocanariensis Rivas Mart., Lous&atilde, Fern.Prieto, E.D&iacute, as, J.C.Costa &amp, C.Aguiar. Age at tree base averaged 33 years, with 60% of the trees between 25 and 50 years old, and only about 15% above 50 years old. This suggests the existence of a secondary forest that is more recent than expected, probably due to human disturbance. The allometric models showed best fit when calculated by stand, suggesting the effect of local environmental conditions on growth rate. Radial growth rate was estimated at 0.68 cm.year&minus, 1. Given the known dominance of this species and the threats affecting natural forests, this baseline study will allow a better understanding of forest distribution and dynamics, and support a more effective forest management approach.

It is estimated that 10% of the worldwide population lives in the vicinity of an active volcano. However, volcanogenic air pollution studies are still outnumbered when compared with anthropogenic air pollution studies, representing an unknown risk to human populations inhabiting volcanic areas worldwide. This study was carried out in the Azorean archipelago of Portugal, in areas with active non-eruptive volcanism. The hydrothermal emissions within the volcanic complex of Furnas (Sao Miguel Island) are responsible for the emission of nearly 1000 tons of CO2 per day, along with H2S, the radioactive gas – radon, among others. Besides the gaseous emissions, metals (e.g., Hg, Cd, Al, Ni) and particulate matter are also released into the environment. We test the hypothesis that chronic exposure to volcanogenic air pollution alters the histomorphology of the bronchioles and terminal bronchioles, using the house mouse, Mus musculus, as bioindicator species. Mus musculus were live-captured at three different locations: two villages with active volcanism and a village without any type of volcanic activity (reference site). The histomorphology of the bronchioles (diameter, epithelium thickness, smooth muscle layer thickness, submucosa thickness and the histological evaluation of the peribronchiolar inflammation) and of the terminal bronchioles (epithelium thickness and classification) were evaluated. Mice chronically exposed to volcanogenic air pollution presented bronchioles with increased epithelial thickness, increased smooth muscle layer, increased submucosa thickness and increased peribronchiolar inflammation. Similarly, terminal bronchioles presented structural alterations consistent with bronchodysplasia. For the first time we demonstrate that chronic exposure to non-eruptive volcanically active environments causes inflammation and histomorphological alterations in mice lower airways consistent with asthma and chronic bronchitis. These results reveal that chronic exposure to non-eruptive volcanic activity represents a risk factor that can affect the health of the respiratory system of humans inhabiting hydrothermal areas.

Hydrothermal areas are potentially hazardous to humans as volcanic gases such as radon (222Rn) are continuously released from soil diffuse degassing. Exposure to radon is estimated to be the second leading cause of lung cancer, but little is known about radon health-associated risks in hydrothermal regions. This cross-sectional study was designed to evaluate the DNA damage in the buccal epithelial cells of individuals chronically exposed to indoor radon in a volcanic area (Furnas volcano, Azores, Portugal) with a hydrothermal system. Buccal epithelial cells were collected from 33 individuals inhabiting the hydrothermal area (Ribeira Quente village) and from 49 individuals inhabiting a non-hydrothermal area (Ponta Delgada city). Indoor radon was measured with Ramon 2.2 detectors. Chromosome damage was measured by micronucleus cytome assay, and RAPD-PCR was used as a complementary tool to evaluate DNA damage, using three 10-mer primers (D11, F1 and F12). Indoor radon concentration correlated positively with the frequency of micronucleated cells (r s = 0.325, p = 0.003). Exposure to radon is a risk factor for the occurrence micronucleated cells in the inhabitants of the hydrothermal area (RR = 1.71; 95% CI, 1.2–2.4; p = 0.003). One RAPD-PCR primer (F12) produced differences in the banding pattern, a fact that can indicate its potential for detecting radon-induced specific genomic alterations. The observed association between chronic exposure to indoor radon and the occurrence of chromosome damage in human oral epithelial cells evidences the usefulness of biological surveillance to assess mutations involved in pre-carcinogenesis in hydrothermal areas, reinforcing the need for further studies with human populations living in these areas.

The exposure to agrochemicals during farming activities affects the function of the reproductive system, as revealed by the increasing worldwide evidence of male infertility amongst farmers. The main objective of this study was to untangle the link between agricultural practices and male reproductive impairment due to chronic exposure to xenobiotics (such as agrochemicals) in conventional and organic farming environments. For this purpose, male wild mice (Mus musculus) populations from sites representing two distinct farming practices (conventional and organic farming systems) were used as bioindicators for observable effects of testicular damage, namely on a set of histological and cellular parameters: (i) relative volumetric density of different spermatogenic cells and interstitial space; (ii) damage in the seminiferous tubules and (iii) apoptotic cells in the germinal epithelium. Results showed that mice from the conventional farming site bioaccumulated higher Pb hepatic loads, while mice from the organic farming site tend to bioaccumulate higher Cd hepatic loads. In general, for the analyzed testicular damage related parameters, mice from the organic farming site showed a similar performance than mice from the reference site. Mice from the conventional farming site stood out not only by underperforming in most studied parameters, while displaying an association between Pb hepatic loads and the observed testicular structural and functional disruption, but also by the increased stress index (Integrated Biomarker Response value). This study highlights the potential damaging effects of conventional farming practices on testicular structure and function, under natural conditions, raising concern about ensuing fertility risks for farmers.

Many evidences have surfaced the adverse effects of environmental pollutants on male reproduction. Volcanogenic pollution is understudied, although it is a well-known source of hazardous contaminants. This study aims to assess the effects of chronic exposure to volcanogenic pollution on wild mice testes by studying: (i) diameter of seminiferous tubules; (ii) relative volumetric density of different spermatogenic cells and interstitial space; (iii) damage in the seminiferous tubules and (iv) apoptotic level in the germinal epithelium. The mice from the polluted site showed higher levels of the selected heavy metals than those from the reference site. The mean diameter of seminiferous tubules and the relative volume occupied by spermatozoa and lumen in exposed mice were significantly lower than in the unexposed group. Contrarily, exposed mice showed a significantly higher relative volume occupied by interstitium, as well as, a higher degree of damage and a significantly higher number of apoptotic cells in the germinal epithelium. Results show that secondary manifestations of volcanic activity can pose a serious risk of testicular injury and therefore for male reproduction.

The alimentary canal of the two-spot ladybird Adalia bipunctata (Linnaeus) (Coleoptera: Coccinellidae) presents the foregut (stomodeum), the midgut (mesenteron) and the hindgut (proctodeum). The shortest region is the foregut and the longest is the midgut. The relative proportions of the main regions were found to be similar for males and females. In the foregut it was possible to distinguish the pharynx, the esophagus and the proventriculus but no crop. The hindgut is composed of the ileum, rectum and rectal canal. Generally the organ width is similar for males and females, but females presented a wider proventriculus. The epithelium of the foregut varied from squamous to simple cuboidal and columnar. In the midgut the epithelium is simple columnar with goblet and regenerative cells. The epithelium of the hindgut varied from simple cuboidal to squamous. Females presented thicker midgut epithelium whereas males presented thicker epithelium in the esophagus. The anatomy of the alimentary canal of A. bipunctata seems to conform to its carnivorous and recent phylogenetic status within the family Coccinellidae.

Few studies were made regarding the pulmonary effects of exposure to volcanogenic air pollution, representing an unrecognized health risk for humans inhabiting non-eruptive volcanically active areas (10% of world human population). We tested the hypothesis whether chronic exposure to air pollution of volcanogenic origin causes lung injury, using wild mice (Mus musculus) as model. Lung injury was determined using histological morphometric parameters, inflammatory status (InfS) and the amount of black silver deposits (BSD). Mice exposed to volcanogenic air pollution have decreased percentage of alveolar space, alveolar perimeter and lung structural functionality (LSF) ratio and, increased alveolar septal thickness, amount of BSD and InfS. For the first time it is evidenced that non-eruptive active volcanism has a high potential to cause lung injury. This study also highlights the usefulness of M. musculus as bioindicator species, and of the developed biomarker of effect LSF ratio, for future animal and/or human biomonitoring programs.

Hydrothermal areas are potentially hazardous to humans as volcanic gases such as radon (