Priority and emerging flame retardants in rivers: Occurrence in water and sediment,Daphnia magna toxicity and risk assessment

The occurrence, partitioning and risk of eight polybrominated diphenyl ethers (PBDEs), nine new brominated (NBFRs) and ten organophosphorus flame retardants (OPFRs) were evaluated in three Spanish rivers suffering different anthropogenic pressures (Nalón, Arga and Besòs). OPFRs were ubiquitous contaminants in water (ΣOPFRs ranging from 0.0076 to 7.2 μg L^− 1) and sediments (ΣOPFRs ranging 3.8 to 824 μg kg^− 1). Brominated flame retardants were not detected in waters, whereas ΣPBDEs ranged from 88 to 812 μg kg^− 1 and decabromodiphenyl ethane (DBDPE) reached 435 μg kg^− 1 in sediments from the River Besòs, the most impacted river. The occurrence of flame retardants in river water and sediment was clearly associated with human activities, since the highest levels occurred near urban and industrial zones and after wastewater treatment plants discharge. Daphnia magna toxicity was carried out for OPFRs, the most ubiquitous flame retardants, considering individual compounds and mixtures. Toxicity of nine tested OPFRs differed largely among compounds, with EC₅₀ values ranging over three magnitude orders (0.31–381 mg L^− 1). Results evidenced that these compounds act by non-polar narcosis, since their toxicity was proportional to their lipophilicity (K_ow). Furthermore, their joint toxicity was additive, which means that single and joint toxicity can be predicted knowing their concentration levels in water using quantitative structure activity relationships (QSARs) and predictive mixture models. Based on these results, a risk assessment considering joint effect was performed calculating and summing risk quotients (RQs) for the water and sediment samples. No significant risk to D. magna (ΣRQs < 1) was observed for any of the monitored rivers.     

Groundwater quality and its health impact: An assessment of dental fluorosis in rural inhabitants of the Main Ethiopian Rift

This study aims to assess the link between fluoride content in groundwater and its impact on dental health in rural communities of the Ethiopian Rift. A total of 148 water samples were collected from two drainage basins within the Main Ethiopian Rift (MER). In the Ziway–Shala basin in particular, wells had high fluoride levels (mean: 9.4 ± 10.5 mg/L; range: 1.1 to 68 mg/L), with 48 of 50 exceeding the WHO drinking water guideline limit of 1.5 mg/L. Total average daily intake of fluoride from drinking groundwater (calculated per weight unit) was also found to be six times higher than the No-Observed-Adverse-Effects-Level (NOAEL) value of 0.06 mg/kg/day. The highest fluoride levels were found in highly-alkaline (pH of 7 to 8.9) groundwater characterized by high salinity; high concentrations of sodium (Na⁺), bicarbonate (HCO₃⁻), and silica (SiO₂); and low concentrations of calcium (Ca^2 +). A progressive Ca^2 + decrease along the groundwater flow path is associated with an increase of fluoride in the groundwater. The groundwater quality problem is also coupled with the presence of other toxic elements, such as arsenic (As) and uranium (U). The health impact of fluoride was evaluated based on clinical examination of dental fluorosis (DF) among local residents using the Thylstrup and Fejerskov index (TFI). In total, 200 rural inhabitants between the ages of 7 and 40 years old using water from 12 wells of fluoride range of 7.8–18 mg/L were examined. Signs of DF (TF score of ≥ 1) were observed in all individuals. Most of the teeth (52%) recorded TF scores of 5 and 6, followed by TF scores of 3 and 4 (30%), and 8.4% had TF scores of 7 or higher. Sixty percent of the teeth exhibited loss of the outermost enamel. Within the range of fluoride contents, we did not find any correlation between fluoride content and DF. Finally, preliminary data suggest that milk intake has contributed to reducing the severity of DF. The study highlights the apparent positive role of milk on DF, and emphasizes the importance of nutrition in management efforts to mitigate DF in the MER and other parts of the world.     

Acute respiratory response to traffic-related air pollution during physical activity performance

BackgroundPhysical activity (PA) has beneficial, whereas exposure to traffic related air pollution (TRAP) has adverse, respiratory effects. Few studies, however, have examined if the acute effects of TRAP upon respiratory outcomes are modified depending on the level of PA.ObjectivesThe aim of our study was to disentangle acute effects of TRAP and PA upon respiratory outcomes and assess the impact of participants TRAP pre-exposure.MethodsWe conducted a real-world crossover study with repeated measures of 30 healthy adults. Participants completed four 2-h exposure scenarios that included either rest or intermittent exercise in high- and low-traffic environments. Measures of respiratory function were collected at three time points. Pre-exposure to TRAP was ascertained from land-use-modeled address-attributed values. Mixed-effects models were used to estimate the impact of TRAP and PA on respiratory measures as well as potential effect modifications.ResultsWe found that PA was associated with a statistically significant increases of FEV₁ (48.5 mL, p = 0.02), FEV₁/FVC (0.64%, p = 0.005) and FEF_25–75% (97.8 mL, p = 0.02). An increase in exposure to one unit (1 μg/m³) of PM_coarse was associated with a decrease in FEV₁ (− 1.31 mL, p = 0.02) and FVC (− 1.71 mL, p = 0.01), respectively. On the other hand, for an otherwise equivalent exposure an increase of PA by one unit (1%Heart rate max) was found to reduce the immediate negative effects of particulate matter (PM) upon PEF (PM_2.5, 0.02 L/min, p = 0.047; PM₁₀, 0.02 L/min p = 0.02; PM_coarse, 0.03 L/min, p = 0.02) and the several hours delayed negative effects of PM upon FVC (PM_coarse, 0.11 mL, p = 0.02). The negative impact of exposure to TRAP constituents on FEV₁/FVC and PEF was attenuated in those participants with higher TRAP pre-exposure levels.ConclusionsOur results suggest that associations between various pollutant exposures and respiratory measures are modified by the level of PA during exposure and TRAP pre-exposure of participants.     

Dietary intake of polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) from fish and meat by residents of Nanjing,China

Concentrations of 14 polybrominated diphenyl ether (PBDEs) and 28 polychlorinated biphenyl (PCBs) congers were measured in 137 samples of fish and meat from Nanjing, a city in the Yangtze River Delta, China. Total concentrations of PBDEs were less in fish (mean of 180 pg/g ww; range 8.0–1100 pg/g ww), but more in non fish foods (mean of 180 pg/g ww; range 15–950 pg/g ww) than those reported from other countries. The total dietary intake of PBDEs and PCBs by humans were 9.9 ng PBDE/d and 870 ng PCB/d, respectively. The daily intake by a 60 kg adult of 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (TEQ_WHO) from PCBs was estimated to be 49 pg ^PCBTEQ_WHO/d (0.82 pg ^PCBTEQ_WHO/kg bw), which is less than the tolerable daily intake suggested by the World Health Organization (WHO). The daily intake of meat and fish accounted for 57.2% and 42.8% of the total intake of ^PCBTEQ_WHO.     

Measurement and health risk assessment of PM2.5, flame retardants,carbonyls and black carbon in indoor and outdoor air in kindergartens in Hong Kong

Indoor air pollution is closely related to children's health. Polybrominated diphenyl ethers (PBDEs) and dechlorane plus (DP) transmitted through indoor PM_2.5 and dust, along with carbonyl compounds and black carbon (BC) aerosol were analysed in five Hong Kong kindergartens. The results showed that 60% of the median PM_2.5 levels (1.3 × 10¹ to 2.9 × 10¹ μg/m³ for indoor; 9.5 to 8.8 × 10¹ μg/m³ for outdoor) in the five kindergartens were higher than the guidelines set by the World Health Organization (2.5 × 10¹ μg/m³). Indoor PM_2.5 mass concentrations were correlated with outdoor PM_2.5 in four of the kindergartens. The PBDEs (0.10–0.64 ng/m³ in PM_2.5; 0.30–2.0 × 10² ng/g in dust) and DP (0.05–0.10 ng/m³ in PM_2.5; 1.3–8.7 ng/g in dust) were detected in 100% of the PM_2.5 and dust samples. Fire retardant levels in the air were not correlated with the levels of dust in this study. The median BC concentrations varied by > 7-fold from 8.8 × 10² ng/m^− 3 to 6.7 × 10³ ng/m^− 3 and cooking events might have caused BC concentrations to rise both indoors and outdoors. The total concentrations of 16 carbonyls ranged from 4.7 × 10¹ μg/m³ to 9.3 × 10¹ μg/m³ indoors and from 1.9 × 10¹ μg/m³ to 4.3 × 10¹ μg/m³ outdoors, whilst formaldehyde was the most abundant air carbonyl. Indoor carbonyl concentrations were correlated with outdoor carbonyls in three kindergartens. The health risk assessment showed that hazard indexes (HIs) HIs of non-cancer risks from PBDEs and DPs were all lower than 0.08, whilst non-cancer HIs of carbonyl compounds ranged from 0.77 to 1.85 indoors and from 0.50 to 0.97 outdoors. The human intake of PBDEs and DP through inhalation of PM_2.5 accounted for 78% to 92% of the total intake. The cancer hazard quotients (HQs) of formaldehyde ranged from 4.5E − 05 to 2.1E − 04 indoors and from 1.9E − 05 to 6.2E − 05 outdoors. In general, the indoor air pollution in the five Hong Kong kindergartens might present adverse effects to children, although different schools showed distinct pollution levels, so indoor air quality might be improved through artificial measures. The data will be useful to developing a feasible management protocol for indoor environments.     

Gene-gene and gene-environment interactions on risk of male infertility: Focus on the metabolites

Infertility affects about 17% couples, and males contribute to half of the cases. Compared with independent effects of genetic and environmental factors, interactions between them help in the understanding of the susceptibility to male infertility. Thus, we genotyped 25 polymorphisms, measured 16 urinary chemical concentrations and explored interactions between gene-gene and gene-environment in 1039 Han Chinese using metabolomic analysis. We first observed that GSTT1 might interact with GSTM1 (P_inter = 6.33 × 10^− 8). Furthermore, an interaction between GSTM1 and 4-n-octylphenol (4-n-OP) was identified (P_inter = 7.00 × 10^− 3), as well as a 2-order interaction among GSTT1, GSTM1 and 4-n-OP (P_inter = 0.04). Subjects with GSTT1-present and GSTM1-null genotypes were susceptible to male infertility when exposed to 4-n-OP (OR = 14.05, 95% CI = 4.78–60.20, P = 2.34 × 10^− 5). Most metabolites identified were involved in the tricarboxylic acid cycle. In conclusion, it is a novel study of the interaction on male infertility from the aspect of metabolomics.     

Endocrine and immunological parameters in individuals involved in Prestige spill cleanup tasks seven years after the exposure

In November 2002 the oil tanker Prestige spilled 63,000 tonnes of heavy oil off the northwest coast of Spain, impacting more than 1000 km of coastline. A general concern led to a huge mobilization of human and technical resources, and more than 300,000 people participated in cleanup activities, which lasted up to 10 months. Some endocrine and immunological alterations were reported in Prestige oil exposed subjects for several months. Therefore, the objective of this study was to evaluate if these alterations are still present seven years after the exposure. Fifty-four individuals exposed for at least 2 months were compared to 50 matched referents. Prolactin and cortisol plasma concentrations, percentages of lymphocyte subsets (CD3⁺, CD4⁺, CD8⁺, CD19⁺, and CD56⁺16⁺), plasma levels of circulating cytokines (interleukin (IL) 2, IL4, IL6, IL10, tumour necrosis factor α, and interferon γ), and serum concentrations of neopterin, tryptophan and kynurenine were determined in peripheral blood samples. Results showed significant differences in exposed individuals vs. referents only in cortisol (increase), kynurenine and %CD16⁺56⁺ lymphocytes (both decrease). Time of exposure to the oil or using protective clothes did not influence the results, but effect of using protective mask was observed on neopterin, %CD8⁺, CD4⁺/CD8⁺ ratio and IL4. Surveillance of the exposed individuals for early detection of possible health problems related to the endocrine or immunological systems is recommended.     

From the shop to the drain — Volatile methylsiloxanes in cosmetics and personal care products

Organosiloxanes are widely used in the formulation of a broad range of cosmetic and personal care products (PCPs), including creams and lotions, bath soaps, shampoo and hair care products to soften, smooth, and moisten. In fact, the intensive and widespread use of organosiloxanes combined with their lipophilic nature, makes them interesting targets for future research, particularly in the toxicology area.This study focused on determining the concentration levels of these compounds in the bestselling brands of PCPs in the Oporto region (Portugal), allowing the estimation of dermal and inhalation exposure to siloxanes and the evaluation of the quantities released to the environment “down-the-drain” and to air. To accomplish this task, a QuEChERS technique (“Quick, Easy, Cheap, Effective, Rugged, and Safe”) was employed to extract the siloxanes from the target PCPs, which has never been tested before. The resulting extract was analysed by gas chromatography–mass spectrometry (GC–MS). The limits of detection varied between 0.17 (L2) and 3.75 ng g^− 1 (L5), being much lower than any values reported in the literature for this kind of products. In general, satisfactory precision (< 10%) and accuracy values (average recovery of 84%) were obtained.123 PCPs were analysed (moisturizers, deodorants, body and hair washes, toilet soaps, toothpastes and shaving products) and volatile methylsiloxanes were detected in 96% of the samples, in concentrations between 0.003 μg g^− 1 and 1203 μg g^− 1. Shampoo exhibited the highest concentration for cyclic and aftershaves for linear siloxanes. Combining these results with the daily usage amounts, an average daily dermal exposure of 25.04 μg kg_bw^− 1 day^− 1 for adults and 0.35 μg kg_bw^− 1 day^− 1 for baby/children was estimated. The main contributors for adult dermal exposure were body moisturizers, followed by facial creams and aftershaves, while for babies/children were body moisturizers, followed by shower gel and shampoo. Similarly, the average daily inhalation exposure was also estimated. Values of 1.56 μg kg_bw^− 1 day^− 1 for adults and 0.03 μg kg_bw^− 1 day^− 1 for babies/children were calculated. An estimate of the siloxanes amount released “down-the-drain” into the sewage systems through the use of toiletries was also performed. An emission per capita between 49.25 and 9574 μg day^− 1 (mean: 1817 μg day^− 1) is expected and shampoo and shower gel presented the higher mean total values (1008 μg day^− 1 and 473.3 μg day^− 1, respectively). In the worst-case scenario, D5 and D3 were the predominant siloxanes in the effluents with 3336 μg day^− 1 and 3789 μg day^− 1, respectively. Regarding the air emissions per capita, values between 8.33 and 6109 μg day^− 1 (mean: 1607 μg day^− 1) are expected and D5 and D6 were the predominant siloxanes.     

Boron exposure through drinking water during pregnancy and birth size

BackgroundBoron is a metalloid found at highly varying concentrations in soil and water. Experimental data indicate that boron is a developmental toxicant, but the few human toxicity data available concern mostly male reproduction.ObjectivesTo evaluate potential effects of boron exposure through drinking water on pregnancy outcomes.MethodsIn a mother-child cohort in northern Argentina (n = 194), 1–3 samples of serum, whole blood and urine were collected per woman during pregnancy and analyzed for boron and other elements to which exposure occurred, using inductively coupled plasma mass spectrometry. Infant weight, length and head circumference were measured at birth.ResultsDrinking water boron ranged 377–10,929 μg/L. The serum boron concentrations during pregnancy ranged 0.73–605 μg/L (median 133 μg/L) and correlated strongly with whole-blood and urinary boron, and, to a lesser extent, with water boron. In multivariable-adjusted linear spline regression analysis (non-linear association), we found that serum boron concentrations above 80 μg/L were inversely associated with birth length (B − 0.69 cm, 95% CI − 1.4; − 0.024, p = 0.043, per 100 μg/L increase in serum boron). The impact of boron appeared stronger when we restricted the exposure to the third trimester, when the serum boron concentrations were the highest (0.73–447 μg/L). An increase in serum boron of 100 μg/L in the third trimester corresponded to 0.9 cm shorter and 120 g lighter newborns (p = 0.001 and 0.021, respectively).ConclusionsConsidering that elevated boron concentrations in drinking water are common in many areas of the world, although more screening is warranted, our novel findings warrant additional research on early-life exposure in other populations.     

Personal exposure to fine particulate matter and blood pressure: A role of angiotensin converting enzyme and its DNA methylation

BackgroundThe underlying intermediate mechanisms about the association between fine particulate matter (PM_2.5) air pollution and blood pressure (BP) were unclear. Few epidemiological studies have explored the potential mediation effects of angiotensin-converting enzyme (ACE) and its DNA methylation.MethodsWe designed a longitudinal panel study with 4 follow-ups among 36 healthy college students in Shanghai, China from December 17, 2014 to July 11, 2015. We measured personal real-time exposure to PM_2.5, serum ACE level, and blood methylation of ACE gene and the repetitive elements. We applied linear mixed-effects models to examine the effects of PM_2.5 on ACE protein, DNA methylation and BP markers. Furthermore, we conducted mediation analyses to evaluate the potential pathways.ResultsAn interquartile range increase (26.78 μg/m³) in 24-h average exposure to PM_2.5 was significantly associated with 1.12 decreases in ACE average methylation (%5mC), 13.27% increase in ACE protein, and increments of 1.13 mmHg in systolic BP, 0.66 mmHg in diastolic BP and 0.82 mmHg in mean arterial pressure. ACE hypomethylation mediated 11.78% (P = 0.03) of the elevated ACE protein by PM_2.5. Increased ACE protein accounted for 3.90 ~ 13.44% (P = 0.35 ~ 0.68) of the elevated BP by PM_2.5. Repetitive-element methylation was also decreased but did not significantly mediate the association between PM_2.5 and BP.ConclusionsThis investigation provided strong evidence that short-term exposure to PM_2.5 was significantly associated with BP, ACE protein and ACE methylation. Our findings highlighted a possible involvement of ACE and ACE methylation in the effects of PM_2.5 on elevating BP.     

Are Chinese consumers at risk due to exposure to metals in crayfish? A bioaccessibility-adjusted probabilistic risk assessment

Freshwater crayfish, the world's third largest crustacean species, has been reported to accumulate high levels of metals, while the current knowledge of potential risk associated with crayfish consumption lags behind that of finfish. We provide the first estimate of human health risk associated with crayfish (Procambarus clarkii) consumption in China, the world's largest producer and consumer of crayfish. We performed Monte Carlo Simulation on a standard risk model parameterized with local data on metal concentrations, bioaccessibility (φ), crayfish consumption rate, and consumer body mass. Bioaccessibility of metals in crayfish was found to be variable (68–95%) and metal-specific, suggesting a potential influence of metal bioaccessibility on effective metal intake. However, sensitivity analysis suggested risk of metals via crayfish consumption was predominantly explained by consumption rate (explaining > 92% of total risk estimate variability), rather than metals concentration, bioaccessibility, or body mass. Mean metal concentrations (As, Cd, Cu, Ni, Pb, Se and Zn) in surveyed crayfish samples from 12 provinces in China conformed to national safety standards. However, risk calculation of φ-modified hazard quotient (HQ) and hazard index (HI) suggested that crayfish metals may pose a health risk for very high rate consumers, with a HI of over 24 for the highest rate consumers. Additionally, the φ-modified increased lifetime risk (ILTR) for carcinogenic effects due to the presence of As was above the acceptable level (10^− 5) for both the median (ILTR = 2.5 × 10^− 5) and 90th percentile (ILTR = 1.8 × 10^− 4), highlighting the relatively high risk of As in crayfish. Our results suggest a need to consider crayfish when assessing human dietary exposure to metals and associated health risks, especially for high crayfish-consuming populations, such as in China, USA and Sweden.     

Air pollution and diabetes association: Modification by type 2 diabetes genetic risk score

Exposure to ambient air pollution (AP) exposure has been linked to type 2 diabetes (T2D) risk. Evidence on the impact of T2D genetic variants on AP susceptibility is lacking. Compared to single variants, joint genetic variants contribute substantially to disease risk. We investigated the modification of AP and diabetes association by a genetic risk score (GRS) covering 63 T2D genes in 1524 first follow-up participants of the Swiss cohort study on air pollution and lung and heart diseases in adults. Genome-wide data and covariates were available from a nested asthma case-control study design. AP was estimated as 10-year mean residential particulate matter < 10 μm (PM₁₀). We computed count-GRS and weighted-GRS, and applied PM₁₀ interaction terms in mixed logistic regressions, on odds of diabetes. Analyses were stratified by pathways of diabetes pathology and by asthma status. Diabetes prevalence was 4.6% and mean exposure to PM₁₀ was 22 μg/m³. Odds of diabetes increased by 8% (95% confidence interval: 2, 14%) per T2D risk allele and by 35% (− 8, 97%) per 10 μg/m³ exposure to PM₁₀. We observed a positive interaction between PM₁₀ and count-GRS on diabetes [OR_interaction = 1.10 (1.01, 1.20)], associations being strongest among participants at the highest quartile of count-GRS [OR: 1.97 (1.00, 3.87)]. Stronger interactions were observed with variants of the GRS involved in insulin resistance [(OR_interaction = 1.22 (1.00, 1.50)] than with variants related to beta-cell function. Interactions with count-GRS were stronger among asthma cases. We observed similar results with weighted-GRS. Five single variants near GRB14, UBE2E2, PTPRD, VPS26A and KCNQ1 showed nominally significant interactions with PM₁₀ (P < 0.05). Our results suggest that genetic risk for T2D may modify susceptibility to air pollution through alterations in insulin sensitivity. These results need confirmation in diabetes cohort consortia.     

The ‘take home’ burden of workplace sensitizers: Flour contamination in bakers' families

BackgroundExposure to flour/flour constituents is a leading cause of occupational asthma. Paternal occupational exposure to flour has been associated with increased likelihood of childhood asthma, raising the possibility of para-occupational exposure whereby family members are exposed to sensitizers ‘taken home’ on contaminated skin/clothing.ObjectiveTo establish whether workplace contamination of skin/clothing with wheat flour allergen (WFA) and fungal α-amylase (FAA) is associated with increased levels of these allergens in bakers' homes.MethodsBakeries in north-east Scotland were invited to participate. Control subjects were recruited from University of Aberdeen staff and students. Exposure assessment was carried out in bakeries, bakers' cars and the homes of bakers and controls using surface wipe and vacuum sampling; samples were analyzed for total protein, FAA and WFA.Results164 wipe samples and 49 vacuum samples were collected from 38 bakers (from 5 bakeries) and 10 controls.Compared to non-bakers, bakers had higher median levels of WFA and FAA in house vacuum samples; the difference was statistically significant for WFA/total protein (515.8 × 10^− 6 vs. 163.7 × 10^− 6, p = 0.031), FAA/total protein ratios (1.45 × 10^− 6 vs. 0.04 × 10^− 6, p < 0.001) and FAA loading (median 1.2 pg/cm² vs. 0.1 pg/cm², p < 0.001) with workplace exposure–home contamination relationships between bakers with higher and lower workplace contamination.We found positive correlations between WFA contamination of the bakers' foreheads and cars (r_s0.57, p = 0.028), foreheads and houses (r_s0.46, p = 0.025), shoes and houses (r_s0.45, p = 0.029); and between FAA contamination of shoes and houses (r_s0.46, p = 0.023), and cars and houses (r_s0.70, p = 0.008). There was no evidence of bakers using work-sourced flour for domestic baking.ConclusionsThis work demonstrates pathways for ‘take home’ exposure of occupationally sourced flour. Taken with our previous work, showing that bakers' children are more likely to have asthma, this supports the need for further investigation to establish whether ‘take home’ of occupationally sourced flour is widespread with health consequences.     

Association between long-term exposure to air pollution and mortality in France: A 25-year follow-up study

IntroductionLong-term exposure to air pollution (AP) has been shown to have an impact on mortality in numerous countries, but since 2005 no data exists for France.ObjectivesWe analyzed the association between long-term exposure to air pollution and mortality at the individual level in a large French cohort followed from 1989 to 2013.MethodsThe study sample consisted of 20,327 adults working at the French national electricity and gas company EDF-GDF. Annual exposure to PM₁₀, PM_10–2.5, PM_2.5, NO₂, O₃, SO₂, and benzene was assessed for the place of residence of participants using a chemistry-transport model and taking residential history into account. Hazard ratios were estimated using a Cox proportional-hazards regression model, adjusted for selected individual and contextual risk factors. Hazard ratios were computed for an interquartile range (IQR) increase in air pollutant concentrations.ResultsThe cohort recorded 1967 non-accidental deaths. Long-term exposures to baseline PM_2.5, PM_10-25, NO₂ and benzene were associated with an increase in non-accidental mortality (Hazard Ratio, HR = 1.09; 95% CI: 0.99, 1.20 per 5.9 μg/m³, PM_10-25; HR = 1.09;95% CI: 1.04, 1.15 per 2.2 μg/m³, NO₂: HR = 1.14; 95% CI: 0.99, 1.31 per 19.3 μg/m³ and benzene: HR = 1.10; 95% CI: 1.00, 1.22 per 1.7 μg/m³).The strongest association was found for PM₁₀: HR = 1.14; 95% CI: 1.05, 1.25 per 7.8 μg/m³. PM₁₀, PM_10-25 and SO₂ were associated with non-accidental mortality when using time varying exposure. No significant associations were observed between air pollution and cardiovascular and respiratory mortality.ConclusionLong-term exposure to fine particles, nitrogen dioxide, sulfur dioxide and benzene is associated with an increased risk of non-accidental mortality in France. Our results strengthen existing evidence that outdoor air pollution is a significant environmental risk factor for mortality. Due to the limited sample size and the nature of our study (occupational), further investigations are needed in France with a larger representative population sample.     

Lake eutrophication and brownification downgrade availability and transfer of essential fatty acids for human consumption

Fish are an important source of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) for birds, mammals and humans. In aquatic food webs, these highly unsaturated fatty acids (HUFA) are essential for many physiological processes and mainly synthetized by distinct phytoplankton taxa. Consumers at different trophic levels obtain essential fatty acids from their diet because they cannot produce these sufficiently de novo. Here, we evaluated how the increase in phosphorus concentration (eutrophication) or terrestrial organic matter inputs (brownification) change EPA and DHA content in the phytoplankton. Then, we evaluated whether these changes can be seen in the EPA and DHA content of piscivorous European perch (Perca fluviatilis), which is a widely distributed species and commonly consumed by humans. Data from 713 lakes showed statistically significant differences in the abundance of EPA- and DHA-synthesizing phytoplankton as well as in the concentrations and content of these essential fatty acids among oligo-mesotrophic, eutrophic and dystrophic lakes. The EPA and DHA content of phytoplankton biomass (mg HUFA g^− 1) was significantly lower in the eutrophic lakes than in the oligo-mesotrophic or dystrophic lakes. We found a strong significant correlation between the DHA content in the muscle of piscivorous perch and phytoplankton DHA content (r = 0.85) as well with the contribution of DHA-synthesizing phytoplankton taxa (r = 0.83). Among all DHA-synthesizing phytoplankton this correlation was the strongest with the dinoflagellates (r = 0.74) and chrysophytes (r = 0.70). Accordingly, the EPA + DHA content of perch muscle decreased with increasing total phosphorus (r² = 0.80) and dissolved organic carbon concentration (r² = 0.83) in the lakes. Our results suggest that although eutrophication generally increase biomass production across different trophic levels, the high proportion of low-quality primary producers reduce EPA and DHA content in the food web up to predatory fish. Ultimately, it seems that lake eutrophication and brownification decrease the nutritional quality of fish for human consumers.     

Recent versus chronic exposure to particulate matter air pollution in association with neurobehavioral performance in a panel study of primary schoolchildren

Children's neuropsychological abilities are in a developmental stage. Recent air pollution exposure and neurobehavioral performance are scarcely studied. In a panel study, we repeatedly administered to each child the following neurobehavioral tests: Stroop Test (selective attention) and Continuous Performance Test (sustained attention), Digit Span Forward and Backward Tests (short-term memory), and Digit-Symbol and Pattern Comparison Tests (visual information processing speed). At school, recent inside classroom particulate matter ≤ 2.5 or 10 μm exposure (PM_2.5, PM₁₀) was monitored on each examination day. At the child's residence, recent (same day up to 2 days before) and chronic (365 days before examination) exposures to PM_2.5, PM₁₀ and black carbon (BC) were modeled. Repeated neurobehavioral test performances (n = 894) of the children (n = 310) reflected slower Stroop Test (p = 0.05) and Digit-Symbol Test (p = 0.01) performances with increasing recent inside classroom PM_2.5 exposure. An interquartile range (IQR) increment in recent residential outdoor PM_2.5 exposure was associated with an increase in average latency of 0.087 s (SE: ± 0.034; p = 0.01) in the Pattern Comparison Test. Regarding chronic exposure at residence, an IQR increment of PM_2.5 exposure was associated with slower performances in the Continuous Performance (9.45 ± 3.47 msec; p = 0.007) and Stroop Tests (59.9 ± 26.5 msec; p = 0.02). Similar results were obtained for PM₁₀ exposure. In essence, we showed differential neurobehavioral changes robustly and adversely associated with recent or chronic ambient exposure to PM air pollution at residence, i.e., with recent exposure for visual information processing speed (Pattern Comparison Test) and with chronic exposure for sustained and selective attention.     

Recreational swimmers' exposure to Vibrio vulnificus and Vibrio parahaemolyticus in the Chesapeake Bay,Maryland, USA

Vibrio vulnificus and Vibrio parahaemolyticus are ubiquitous in the marine–estuarine environment, but the magnitude of human non-ingestion exposure to these waterborne pathogens is largely unknown. We evaluated the magnitude of dermal exposure to V. vulnificus and V. parahaemolyticus among swimmers recreating in Vibrio-populated waters by conducting swim studies at four swimming locations in the Chesapeake Bay in 2009 and 2011. Volunteers (n = 31) swam for set time periods, and surface water (n = 25) and handwash (n = 250) samples were collected. Samples were analyzed for Vibrio concentrations using quantitative PCR. Linear and logistic regressions were used to evaluate factors associated with recreational exposures. Mean surface water V. vulnificus and V. parahaemolyticus concentrations were 1128 CFU mL^− 1 (95% confidence interval (CI): 665.6, 1591.4) and 18 CFU mL^− 1 (95% CI: 9.8, 26.1), respectively, across all sampling locations. Mean Vibrio concentrations in handwash samples (V. vulnificus, 180 CFU cm^− 2 (95% CI: 136.6, 222.5); V. parahaemolyticus, 3 CFU cm^− 2 (95% CI: 2.4, 3.7)) were significantly associated with Vibrio concentrations in surface water (V. vulnificus, p < 0.01; V. parahaemolyticus, p < 0.01), but not with salinity or temperature (V. vulnificus, p = 0.52, p = 0.17; V. parahaemolyticus, p = 0.82, p = 0.06). Handwashing reduced V. vulnificus and V. parahaemolyticus on subjects' hands by approximately one log (93.9%, 89.4%, respectively). It can be concluded that when Chesapeake Bay surface waters are characterized by elevated concentrations of Vibrio, swimmers and individuals working in those waters could experience significant dermal exposures to V. vulnificus and V. parahaemolyticus, increasing their risk of infection.     

The synergistic toxicity of the multiple chemical mixtures: Implications for risk assessment in the terrestrial environment

The combined toxicity of five insecticides (chlorpyrifos, avermectin, imidacloprid, λ-cyhalothrin, and phoxim), two herbicides (atrazine and butachlor) and a heavy metal (cadmium) has been examined with the earthworm acute toxicity test. Toxicological interactions of these chemicals in four, five, six, seven, and eight-component mixtures were studied using the combination-index (CI) equation method. In four-component and five-component mixtures, the synergistic effects predominated at lower effect levels, while the patterns of interactions found in six, seven, and eight-component mixtures displayed synergism. The λ-CY + IMI + BUT + ATR + CPF + PHO combination displayed the most strongly synergistic interaction, with CI values ranging from 0.09 to 0.15. The nature of the interaction changes with the effect level and the relevance of synergistic effects increase with the complexity of the mixture. The CI method was compared with the classical models of concentration addition (CA) and independent action (IA) and we found that the CI method could accurately predict the combined toxicity. The predicted synergism resulted from co-existence of the pesticides and the heavy metal especially at low effect levels may have important implications in risk assessment for the real terrestrial environment.     

The contributions to long-term health-relevant particulate matter at the UK EMEP supersites between 2010 and 2013: Quantifying the mitigation challenge

Human health burdens associated with long-term exposure to particulate matter (PM) are substantial. The metrics currently recommended by the World Health Organization for quantification of long-term health-relevant PM are the annual average PM₁₀ and PM_2.5 mass concentrations, with no low concentration threshold. However, within an annual average, there is substantial variation in the composition of PM associated with different sources. To inform effective mitigation strategies, therefore, it is necessary to quantify the conditions that contribute to annual average PM₁₀ and PM_2.5 (rather than just short-term episodic concentrations). PM₁₀, PM_2.5, and speciated water-soluble inorganic, carbonaceous, heavy metal and polycyclic aromatic hydrocarbon components are concurrently measured at the two UK European Monitoring and Evaluation Programme (EMEP) ‘supersites’ at Harwell (SE England) and Auchencorth Moss (SE Scotland). In this work, statistical analyses of these measurements are integrated with air-mass back trajectory data to characterise the ‘chemical climate’ associated with the long-term health-relevant PM metrics at these sites. Specifically, the contributions from different PM concentrations, months, components and geographic regions are detailed. The analyses at these sites provide policy-relevant conclusions on mitigation of (i) long-term health-relevant PM in the spatial domain for which these sites are representative, and (ii) the contribution of regional background PM to long-term health-relevant PM.At Harwell the mean (± 1 sd) 2010–2013 annual average concentrations were PM₁₀ = 16.4 ± 1.4 μg m^− 3 and PM_2.5 = 11.9 ± 1.1 μg m^− 3 and at Auchencorth PM₁₀ = 7.4 ± 0.4 μg m^− 3 and PM_2.5 = 4.1 ± 0.2 μg m^− 3. The chemical climate state at each site showed that frequent, moderate hourly PM₁₀ and PM_2.5 concentrations (defined as approximately 5–15 μg m^− 3 for PM₁₀ and PM_2.5 at Harwell and 5–10 μg m^− 3 for PM₁₀ at Auchencorth) determined the magnitude of annual average PM₁₀ and PM_2.5 to a greater extent than the relatively infrequent high, episodic PM₁₀ and PM_2.5 concentrations. These moderate PM₁₀ and PM_2.5 concentrations were derived across the range of chemical components, seasons and air-mass pathways, in contrast to the highest PM concentrations which tended to associate with specific conditions. For example, the largest contribution to moderate PM₁₀ and PM_2.5 concentrations – the secondary inorganic aerosol components, specifically NO₃⁻ – were accumulated during the arrival of trajectories traversing the spectrum of marine, UK, and continental Europe areas. Mitigation of the long-term health-relevant PM impact in the regions characterised by these two sites requires multilateral action, across species (and hence source sectors), both nationally and internationally; there is no dominant determinant of the long-term PM metrics to target.     

A geographical comparison of mercury in seabirds in the eastern Canadian Arctic

Mercury (Hg) is a potentially toxic metal ubiquitous in arctic biota. Livers of adult thick-billed murres (Uria lomvia) and northern fulmars (Fulmarus glacialis) sampled from several locations in the eastern Canadian Arctic during 2007–2008 were analyzed for total Hg in order to assess geographical patterns. Thick-billed murres were collected from five colonies (Coats Island, Digges Island, Akpatok Island, Prince Leopold Island, Minarets) and northern fulmars from two colonies (Prince Leopold Island, Minarets). Murres at the two high Arctic colonies of Prince Leopold Island and the Minarets had significantly higher (two-fold) Hg concentrations (4.13 ± 019 μg g^− 1 dw and 4.41 ± 0.33 μg g^− 1 dw, respectively) than at the three low Arctic colonies (colony means of 1.62, 1.99 and 2.15 μg g^− 1 dw). The differences in Hg concentrations observed between high and low Arctic murre colonies may reflect a combination of different source regions for Hg, as well as a recent dietary shift among low Arctic murres. Fulmars from Prince Leopold Island had significantly higher Hg levels (6.99 ± 1.13 μg g^− 1 dw) than those from the Minarets (3.42 ± 0.53 μg g^− 1 dw) which may reflect different Hg deposition and methylation patterns on both summer and winter feeding areas. Although there is no evidence linking Hg to adverse population effects in either murres or fulmars at the colonies sampled, levels in some Canadian Arctic marine birds have increased over recent decades and, therefore, continued monitoring, particularly of the high Arctic colonies, is warranted.