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Mosquito-borne diseases like Rift Valley Fever and Malaria that cause serious health threat to human and livestock populations are known to correlate with the tremendous increase of associated mosquito vectors following periods of widespread and heavy rainfall. In the Barkedji area, Senegal, rainfall occur only during the July–October wet season, and mosquito breeding sites are provided by relatively small temporary ponds, which account for the vast majority of the water surfaces during the rainy season. Given that rain fed ponds play a key role in the epidemiology of the mosquito-borne diseases, we have developed an approach allowing to model the flooding/drying dynamics of rain fed ponds in the Barkedji area by combining the detection of ponds using optical remote sensing techniques, field data on a small set of monitored ponds and modeling of both the pond profile, shapes and the flooding/drying dynamics at the single-pond level for each pond in the entire region. As a result, we have computed on output the daily flooding/drying dynamics for each of the 1345 rain fed ponds detected in Barkedji area as a function of the daily rainfall in input. As dry and fluctuating ponds are less productive in mosquitoes, the ponds are characterizes in terms of flooding-drying fluctuations and of resistance to dryness by computing the total number of time per year a pond dries out and the pond lifetime, respectively. And, clusters of ponds with identical behavior, i.e., clusters of temporary, semi-permanent and permanent ponds, were subsequently identified. As a perspective, we show how this work can be used for modelling mosquito population dynamics and addressing the issues of associated impacts of climate change. [ABSTRACT FROM AUTHOR]

It is undeniable that exposure to outdoor air pollution impacts the health of populations and therefore constitutes a public health problem. Any actions or events causing variations in air quality have repercussions on populations' health. Faced with the worldwide COVID-19 health crisis that began at the end of 2019, the governments of several countries were forced, in the beginning of 2020, to put in place very strict containment measures that could have led to changes in air quality. While many works in the literature have studied the issue of changes in the levels of air pollutants during the confinements in different countries, very few have focused on the impact of these changes on health risks. In this work, we compare the 2020 period, which includes two lockdowns (March 16 - May 10 and a partial shutdown Oct. 30 - Dec. 15) to a reference period 2015–2019 to determine how these government-mandated lockdowns affected concentrations of NO 2 , O 3 , PM 2.5 , and PM 10 , and how that affected human health factors, including low birth weight, lung cancer, mortality, asthma, non-accidental mortality, respiratory, and cardiovascular illnesses. To this end, we structured 2020 into four periods, alternating phases of freedom and lockdowns characterized by a stringency index. For each period, we calculated (1) the differences in pollutant levels between 2020 and a reference period (2015–2019) at both background and traffic stations; and (2) the resulting variations in the epidemiological based relative risks of health outcomes. As a result, we found that relative changes in pollutant levels during the 2020 restriction period were as follows: NO 2 (−32%), PM 2.5 (−22%), PM 10 (−15%), and O 3 (+10.6%). The pollutants associated with the highest health risk reductions in 2020 were PM 2.5 and NO 2, while PM 10 and O 3 changes had almost no effect on health outcomes. Reductions in short-term risks were related to reductions in PM 2.5 (−3.2% in child emergency room visits for asthma during the second lockdown) and NO 2 (−1.5% in hospitalizations for respiratory causes). Long-term risk reductions related to PM 2.5 were low birth weight (−8%), mortality (−3.3%), and lung cancer (−2%), and to NO 2 for mortality (−0.96%). Overall, our findings indicate that the confinement period in 2020 resulted in a substantial improvement in air quality in the Grenoble area. [Display omitted] • Global level changes in 2020: NO 2 (−32%), PM 2.5 (−22%), PM 10 (−15%) and O 3 (+10.6%). • Health risk impacts were mainly related to changes in PM 2.5 and NO 2 levels. • Short-term risks of child asthma (−3%) and hospitalization for respiratory diseases (−2%). • Long-term risks of low birth weight (−8%), mortality (−4%), and lung cancer (−2%). [ABSTRACT FROM AUTHOR]

The aggressiveness of mosquitoes towards humans is often measured on different time scales but never continuously because of the amount of work required in practice. We developed a general downscaling method to simulate the aggressiveness of mosquitoes over short and long time periods based on a series of imbricated generalized linear models that link aggressiveness with explicative environmental variables according to each time scale. This method was applied to observations of Culex modestus; in order to simulate hourly aggressiveness during the favorable season and describe the periods of low, medium and high risk of being bitten by C. modestus. The higher risk of being bitten is found (i) at the beginning of summer during twilight and at night; (ii) later in summer during twilight, day light and zenith and (iii) at the end of summer during the afternoon only. The lower risk is found during (i) the day at the beginning of March and from the end of April to the end of May and (ii) the night from March to April inclusive. The risk is moderate for the remaining periods. [Copyright &y& Elsevier]

Abstract Background Millions of workers are exposed to carcinogenic polycyclic aromatic hydrocarbon (PAH) mixtures. The toxicity of PAH mixtures is variable and depends on the composition of the mixture, which is related to the emission sources. Although several indicators exist, the cancer risk estimation associated with occupational exposure to PAHs is poorly known. Objectives To assess the risk of lung cancer associated with PAHs in several industries using the atmospheric concentrations of benzo[ a ]pyrene (BaP) as a proxy. Methods A total of 93 exposure groups belonging to 9 industries were investigated. Eight indicators found in the literature were compared to assess risks. A consensual indicator was used to estimate lung cancer risks. Results Approximately 30% of the exposure groups were above the maximal risk level of the European Union (10−4). The risk probabilities were >10−3 for coke and silicon production; >10−4 for the manufacturing of carbon products and aluminum production; >10−5 for foundries and combustion processes; >10−6 for the use of lubricating oils and engine exhaust emissions; and >10−7 for bitumen. The risk probabilities were highly variable within industries (from 1 to 1000 likelihood). A total of 27 (95% CI: 0.1–54) contemporary additional lung cancer cases could be expected per year in the French exposed population based on estimations using published data. Conclusion This study provides an overview of cancer risk estimation in many industries. Despite efforts and changes that had been made to decrease risks, PAHs remain a sanitary threat for people exposed to these pollutants in occupational environments. Graphical abstract Unlabelled Image Highlights • The risk of developing lung cancer was variable (1 to 103 likelihood) among industries. • 27 out of 93 exposure groups in industries were found to exceed the EU risk threshold. • Industries using products derived from coal were the most at risk of lung cancer. • 27 contemporary additional lung cancer cases per year could be expected in France. • Despite efforts and changes made in the past, PAHs remain a sanitary threat. [ABSTRACT FROM AUTHOR]

Background: Millions of workers are exposed to polycyclic aromatic hydrocarbons (PAHs), a well-known family of carcinogens, but occupational exposure data about PAH mixture compositions are scarce.Objectives: To provide a detailed picture of airborne PAH exposures encountered in the French industrial landscape over the previous 20 years and to identify determinants driving exposures.Methods: Results from 1643 airborne samples of 16 gaseous and particulate PAHs implemented into the Exporisq HAP database from 1995 to 2014 were used to describe exposure levels and aerosol chemical composition in many industries and activities. Compliance of benzo[a]pyrene (BaP) levels with several existing occupational exposure limits for long-term exposure was assessed.Results: BaP levels were lower than those reported in the literature, but the level and composition of PAH mixtures were highly variable between and within industries. Numerous exposure determinants (e.g., product composition, type and temperature of process, ventilation and confinement) were assumed to explain these differences. The highest levels were found in industries using products derived from coal (aluminum, silicon, and coke production, manufacturing of carbon products and foundries), with mean BaP levels up to 23 times higher than the French recommended value of 150 ng/m3. Forty-seven percent of the occupational activities exceeded this value. Conversely, exposures resulting from petroleum-derived products were relatively low.Conclusions: As health effects depend on PAH levels but also on the composition of the mixture, exposure assessments must characterize the entire mixtures and record specific determinants to define homogeneous exposure groups and to accurately assess health risks. [ABSTRACT FROM AUTHOR]

Background The health risk assessment associated with polycyclic aromatic hydrocarbon (PAH) mixtures faces three main issues: the lack of knowledge regarding occupational exposure mixtures, the accurate chemical characterization and the estimation of cancer risks. Objectives To describe industries in which PAH exposures are encountered and construct working context–exposure function matrices, to enable the estimation of both the PAH expected exposure level and chemical characteristic profile of workers based on their occupational sector and activity. Methods Overall, 1729 PAH samplings from the Exporisq-HAP database (E-HAP) were used. An approach was developed to (i) organize E-HAP in terms of the most detailed unit of description of a job and (ii) structure and subdivide the organized E-HAP into groups of detailed industry units, with each group described by the distribution of concentrations of gaseous and particulate PAHs, which would result in working context–exposure function matrices. PAH exposures were described using two scales: phase (total particulate and gaseous PAH distribution concentrations) and congener (16 congener PAH distribution concentrations). Results Nine industrial sectors were organized according to the exposure durations, short-term, mid-term and long-term into 5, 36 and 47 detailed industry units, which were structured, respectively, into 2, 4, and 7 groups for the phase scale and 2, 3, and 6 groups for the congener scale, corresponding to as much distinct distribution of concentrations of several PAHs. For the congener scale, which included groups that used products derived from coal, the correlations between the PAHs were strong; for groups that used products derived from petroleum, all PAHs in the mixtures were poorly correlated with each other. Conclusions The current findings provide insights into both the PAH emissions generated by various industrial processes and their associated occupational exposures and may be further used to develop risk assessment analyses of cancers associated with PAH mixtures. [ABSTRACT FROM AUTHOR]