An interlaboratory comparison of nanosilver characterisation and hazard identification: Harmonising techniques for high quality data

Within the FP7 EU project NanoValid a consortium of six partners jointly investigated the hazard of silver nanoparticles (AgNPs) paying special attention to methodical aspects that are important for providing high-quality ecotoxicity data. Laboratories were supplied with the same original stock dispersion of AgNPs. All partners applied a harmonised procedure for storage and preparation of toxicity test suspensions. Altogether ten different toxicity assays with a range of environmentally relevant test species from different trophic levels were conducted in parallel to AgNP characterisation in the respective test media. The paper presents a comprehensive dataset of toxicity values and AgNP characteristics like hydrodynamic sizes of AgNP agglomerates and the share (%) of Ag⁺-species (the concentration of Ag⁺-species in relation to the total measured concentration of Ag). The studied AgNP preparation (20.4 ± 6.8 nm primary size, mean total Ag concentration 41.14 mg/L, 46–68% of soluble Ag⁺-species in stock, 123.8 ± 12.2 nm mean z-average value in dH₂O) showed extreme toxicity to crustaceans Daphnia magna, algae Pseudokirchneriella subcapitata and zebrafish Danio rerio embryos (EC50 < 0.01 mg total Ag/L), was very toxic in the in vitro assay with rainbow trout Oncorhynchus mykiss gut cells (EC50: 0.01–1 mg total Ag/L); toxic to bacteria Vibrio fischeri, protozoa Tetrahymena thermophila (EC50: 1–10 mg total Ag/L) and harmful to marine crustaceans Artemia franciscana (EC50: 10–100 mg total Ag/L). Along with AgNPs, also the toxicity of AgNO₃ was analyzed. The toxicity data revealed the same hazard ranking for AgNPs and AgNO₃ (i.e. the EC50 values were in the same order of magnitude) proving the importance of soluble Ag⁺-species analysis for predicting the hazard of AgNPs. The study clearly points to the need for harmonised procedures for the characterisation of NMs. Harmonised procedures should consider: (i) measuring the AgNP properties like hydrodynamic size and metal ions species in each toxicity test medium at a range of concentrations, and (ii) including soluble metal salt control both in toxicity testing as well as in Ag⁺-species measurements. The present study is among the first nanomaterial interlaboratory comparison studies with the aim to improve the hazard identification testing protocols.     

Mechanistic polychlorinated biphenyl exposure modeling of mothers in the Canadian Arctic: the challenge of reliably establishing dietary composition

BackgroundTraditional food (TF) consumption represents the main route of persistent organic pollutant (POP) exposure for indigenous Arctic Canadians. Ongoing dietary transitions away from TFs and toward imported foods (IFs) may contribute to decreasing POP exposures observed in these groups.MethodsTo explore this issue, we combined the global fate and transport model GloboPOP and the human food chain bioaccumulation model ACC-Human Arctic to simulate polychlorinated biphenyl (PCB) exposure in two indigenous Arctic Canadian communities from the Inuvik region, Northwest Territories and Baffin region, Nunavut. Using dietary survey information from initial (1996–98) and follow-up (2005–07) biomonitoring campaigns in Inuvik and Baffin, we simulated PCB exposures (PCB-118, -138, -153, and -180) for each individual study participant and also whole study populations.ResultsTF intake rates, particularly of marine mammals (MMs), were the most important predictors of modeled PCB exposure, while TF consumption did not associate consistently with measured PCB exposures. Further, reported mean TF intake increased from baseline to follow-up in both Inuvik (from 8 to 183 g d^− 1) and Baffin (from 60 to 134 g d^− 1), opposing both the expected dietary transition direction and the observed decrease in human PCB exposures in these communities (ΣPCB Inuvik: from 43 to 29 ng g lipid^− 1, ΣPCB Baffin: from 213 to 82 ng g lipid^− 1). However dietary questionnaire data are frequently subject to numerous biases (e.g., recall, recency, confirmation), and thus casts doubt on the usefulness of these data.ConclusionsUltimately, our model's capability to reproduce historic PCB exposure data in these two groups was highly sensitive to TF intake, further underscoring the importance of accurate TF consumption reporting, and clarification of the role of dietary transitions in future POP biomonitoring of indigenous Arctic populations.     

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.     

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.     

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.     

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.     

Levels and profiles of PCDD/Fs,PCBs in mothers' milk in Shenzhen of China: Estimation of breast-fed infants’ intakes

Sixty breast milk samples were collected in Shenzhen, China from July to November in 2007. The samples were analyzed of the concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and polychlorinated biphenyls (PCBs). The range of upper-bound for ∑ TEQ-(PCDD/Fs + PCBs) in the samples was 4.10–35.3 pg TEQ g^− 1 lipid (median: 10.6 pg TEQ g^− 1 lipid; mean: 11.9 pg TEQ g^− 1 lipid). The levels of the measured contaminants in the breast milk had significant correlations with the length of inhabitation period in Shenzhen (r = 0.487, p < 0.05 for PCDD/Fs, r = 0.431, p < 0.05 for PCBs and r = 0.478, p < 0.05 for ∑ TEQ-(PCDD/Fs + PCBs)), and the consumption rate of fish (r = 0.366, p < 0.05 for PCDD/Fs, r = 0.486, p < 0.05 for PCBs and r = 0.416, p < 0.05 for ∑ TEQ-(PCDD/Fs + PCBs)), respectively. Moreover, significant positive correlations were also detected between the participant's age (r = 0.305, p < 0.05 for ∑ TEQ-PCBs and r = 0.275, p < 0.05 for ∑ TEQ-(PCDD/Fs + PCBs)) and the body burdens of these contaminants respectively. It is estimated that the daily intake (EDI) of the sum of PCDD/Fs and DL-PCBs by the breast-fed infants was 5.60–161 pg TEQ kg^− 1 bw per day (mean: 48.2 pg TEQ kg^− 1 bw per day; median: 42.2 pg TEQ kg^− 1 bw per day). The result showed that both the body burdens of PCDD/Fs and PCBs of the recruit population and the calculated EDI of the breast-fed infants were higher than those in the non-exposed areas in mainland China. This suggests that continuous surveillance on PCDD/Fs and PCBs levels in human milk is critical to more precisely evaluate the human health risk posed by the negative environmental impact in Shenzhen in the future.     

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.     

Fate,distribution, and contrasting temporal trends of perfluoroalkyl substances (PFASs) in Lake Ontario,Canada

Lake Ontario water and sediment collected from tributary, nearshore, and open lake sites were analyzed for perfluoroalkyl substances (PFASs), namely perfluoroalkyl carboxylic acids (PFCAs, F(CF₂)_nCO₂⁻; n = 6-11,13) and perfluoroalkane sulfonic acids (PFSAs, F(CF₂)_nSO₃⁻; n = 6,8,10). Survey results of surface sediment and water indicated that shorter chained PFASs were predominant in and near urban/industrial area watersheds, while longer chained PFASs were predominant in fine-grained sediment from major depositional basins. Niagara River suspended solids (1981–2006) demonstrated temporal trends that may have been influenced by recent changes in North American production and use of PFASs. Perfluorooctane sulfonate (PFOS) reached a peak concentration in 2001 of 1.1 ng/g, followed by a decrease from 2001 to 2006 (half-life = 9 years). Perfluorooctanoic acid (PFOA) increased from 2001 to 2006 (doubling time = 2 years) reaching a peak concentration of 0.80 ng/g. In contrast, three sediment cores from western, central, and eastern Lake Ontario showed increasing temporal trends to surface sediment for all PFASs. PFOA and PFOS concentrations increased from 1988 to 2004 (doubling time = ~ 4 years) in the western Lake Ontario core. The observed variations in temporal trends from different environmental compartments may be a result of the physico-chemical properties of PFASs, ongoing emissions, and the environmental transformation and degradation of PFAS precursor compounds.     

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.     

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.     

Uranium in drinking-water: A unique case of guideline value increases and discrepancies between chemical and radiochemical guidelines

BackgroundUranium represents a unique case for an element naturally present in the environment, as its chemical guideline value in drinking water significantly increased from 2 μg/L in 1998 up to 15 μg/L in 2004 and then to 30 μg/L in 2011, to date corresponding to a multiplication factor of 15 within a period of just 13 years.ObjectivesIn this commentary we summarize the evolution of uranium guideline values in drinking-water based on both radiological and chemical aspects, emphasizing the benefit of human studies and their contribution to recent recommendations. We also propose a simpler and better consistency between radiological and chemical values.DiscussionThe current chemical guideline value of 30 μg/L is still designated as provisional because of scientific uncertainties regarding uranium toxicity. During the same period, the radiological guideline for ²³⁸U increased from 4 Bq/L to 10 Bq/L while that for ²³⁴U decreased from 4 Bq/L to 1 Bq/L. These discrepancies are discussed here, and a value of 1 Bq/L for all uranium isotopes is proposed to be more consistent with the current chemical value of 30 μg/L.ConclusionContinuous progress in the domains of toxicology and speciation should enable a better interpretation of the biological effects of uranium in correlation with epidemiological human studies. This will certainly aid future proposals for uranium guideline values.     

Exposure to fine particle matter,nitrogen dioxide and benzene during pregnancy and cognitive and psychomotor developments in children at 15 months of age

BackgroundPrenatal exposure to air pollutants has recently been identified as a potential risk factor for neuropsychological impairment.ObjectivesTo assess whether prenatal exposure to fine particulate matter (PM_2.5), nitrogen dioxide (NO₂) and benzene were associated with impaired development in infants during their second year of life.MethodsRegression analyses, based on 438 mother–child pairs, were performed to estimate the association between mother exposure to air pollutants during pregnancy and neurodevelopment of the child. The average exposure to PM_2.5, NO₂ and benzene over the whole pregnancy was calculated for each woman. During the second year of life, infant neuropsychological development was assessed using the Bayley Scales of Infant Development. Regression analyses were performed to estimate the association between exposure and outcomes, accounting for potential confounders.ResultsWe estimated that a 1 μg/m³ increase during pregnancy in the average levels of PM_2.5 was associated with a − 1.14 point decrease in motor score (90% CI: − 1.75; − 0.53) and that a 1 μg/m³ increase of NO₂ exposure was associated with a − 0.29 point decrease in mental score (90% CI: − 0.47; − 0.11). Benzene did not show any significant association with development. Considering women living closer (≤ 100 m) to metal processing activities, we found that motor scores decreased by − 3.20 (90% CI: − 5.18; − 1.21) for PM_2.5 and − 0.51 (− 0.89; − 0.13) for NO₂, while mental score decreased by − 2.71 (90% CI: − 4.69; − 0.74) for PM_2.5, and − 0.41 (9% CI: − 0.76; − 0.06) for NO₂.ConclusionsOur findings suggest that prenatal residential exposure to PM_2.5 and NO₂ adversely affects infant motor and cognitive developments. This negative effect could be higher in the proximity of metal processing plants.     

Route-specific daily uptake of organochlorine pesticides in food,dust, and air by Shanghai residents,China

Dichlorodiphenyltrichloroethane (DDT) and hexachlorocyclohexanes (HCHs) are widely detected in the environment, although they have been banned in China since 1980s. To better understand the route-specific daily uptake of the pesticides by humans, a total of 322 food, dust, and air samples were collected in Shanghai, China, during 2008–2011. The median concentrations were 0.2–126.6 and 0.03–1.6 ng/g wet weight for DDTs (DDT and its metabolites) and HCHs, respectively, in different types of foods. The values in dust (indoors and outdoors) were 5.7–29.8 and 1.3–5.4 ng/g, and 13.9 × 10^− 3 and 2.6 × 10^− 3 ng/m³ in air (gas + particle) for DDTs and HCHs, respectively. The daily uptake of a pesticide by humans was calculated via the pesticide intake multiplied by its uptake efficiency. The uptake efficiencies of DDTs and HCHs in food through human intestines were estimated using bioaccessibility measured via an in vitro method simulating the human gastrointestinal digestion process. The total daily uptakes of DDTs and HCHs through three routes (i.e., ingestion, inhalation, and dermal contact) were 79.4 and 4.9 ng/day, respectively, for children, and 131.1 and 8.0 ng/day, respectively, for adults. Ingestion via food and dust was the main route of human exposure to the pesticides, and the daily uptake of the pesticides via food consumption accounted for 95.0–99.2% of the total.     

Organophosphate pesticide exposure and perinatal outcomes in Shanghai,China

Although pesticide use is widespread in China, little is known about levels of exposure to organophosphate pesticides in the population and its potential adverse health effects. We investigated levels of organophosphate exposure in pregnant women and the association between organophosphate exposure and perinatal outcomes in Shanghai, China, by enrolling 187 healthy pregnant women between September 2006 and January 2007. Pesticide exposure was assessed by a questionnaire administered to the mothers in the hospital after delivery as well as by analyses of maternal urinary nonspecific metabolites of organophosphate pesticides (dimethyl and diethyl phosphates). Information on birth weight and length was collected from medical records. Geometric means of metabolites were 25.75 μg/L for dimethylphosphate (DMP); 11.99 μg/L for dimethylthiophosphate (DMTP); 9.03 μg/L for diethylphosphate (DEP); and 9.45 μg/L for diethyldithiophosphate (DETP). We found that a log unit increase in urinary DEP was associated with a decrease in gestational duration in girls by 1.79 weeks. [ß_adjusted = − 1.79 weeks per log₁₀ unit increase; 95% confidence interval (CI), −2.82 to − 0.76; p = 0.001]. These data suggest that high pesticide level might adversely affect duration of gestation although this association was not present among boys. No associations for any of the organophosphate exposure measures were present for birth weight and length, suggesting that organophosphate pesticides may have no effects on fetal growth. Given that maternal urine pesticide levels in Shanghai were much higher than those reported in developed countries, more studies on the effects of in utero organophosphate exposure on fetal growth and child neurodevelopment are warranted.     

Respiratory medication sales and urban air pollution in Brussels (2005 to 2011)

BackgroundWe investigated the associations between daily sales of respiratory medication and air pollutants in the Brussels-Capital Region between 2005 and 2011.MethodsWe used over-dispersed Poisson Generalized Linear Models to regress daily individual reimbursement data of prescribed asthma and COPD medication from the social security database against each subject's residential exposure to outdoor particulate matter (PM₁₀) or NO₂ estimated, by interpolation from monitoring stations. We calculated cumulative risk ratios (RR) and their 95% confidence intervals (CI) for interquartile ranges (IQR) of exposure for different windows of past exposure for the entire population and for seven age groups.ResultsMedian daily concentrations of PM₁₀ and NO₂ were 25 μg/m³ (IQR = 17.1) and 38 μg/m³ (IQR = 20.5), respectively. PM₁₀ was associated with daily medication sales among individuals aged 13 to 64 y. For NO₂, significant associations were observed among all age groups except > 84 y. The highest RR were observed for NO₂, among adolescents, including three weeks lags (RR = 1.187 95%CI: 1.097–1.285).ConclusionThe associations found between temporal changes in exposure to air pollutants and daily sales of respiratory medication in Brussels indicate that urban air pollution contributes to asthma and COPD morbidity in the general population.     

Combustion particles emitted during church services: Implications for human respiratory health

Burning candles and incense generate particulate matter (PM) that produces poor indoor air quality and may cause human pulmonary problems. This study physically characterised combustion particles collected in a church during services. In addition, the emissions from five types of candles and two types of incense were investigated using a combustion chamber. The plasmid scission assay was used to determine the oxidative capacities of these church particles. The corresponding risk factor (CRf) was derived from the emission factor (Ef) and the oxidative DNA damage, and used to evaluate the relative respiratory exposure risks. Real-time PM measurements in the church during candle–incense burning services showed that the levels (91.6 μg/m³ for PM₁₀; 38.9 μg/m³ for PM_2.5) exceeded the European Union (EU) air quality guidelines. The combustion chamber testing, using the same environmental conditions, showed that the incense Ef for both PM₁₀ (490.6–587.9 mg/g) and PM_2.5 (290.1–417.2 mg/g) exceeded that of candles; particularly the PM_2.5 emissions. These CRf results suggested that the exposure to significant amounts of incense PM could result in a higher risk of oxidative DNA adducts (27.4–32.8 times) than tobacco PM. The generation and subsequent inhalation of PM during church activities may therefore pose significant risks in terms of respiratory health effects.     

Cleaning-induced arsenic mobilization and chromium oxidation from CCA-wood deck: Potential risk to children

Concern about children's exposure to arsenic (As) from wood treated with chromated-copper-arsenate (CCA) led to its withdrawal from residential use in 2004. However, due to its effectiveness, millions of American homes still have CCA-wood decks on which children play. This study evaluated the effects of three deck-cleaning methods on formation of dislodgeable As and hexavalent chromium (CrVI) on CCA-wood surfaces and in leachate. Initial wipes from CCA-wood wetted with water showed 3–4 times more dislodgeable As than on dry wood. After cleaning with a bleach solution, 9.8–40.3 μg/100 cm² of CrVI was found on the wood surface, with up to 170 μg/L CrVI in the leachate. Depending on the cleaning method, 699–2473 mg of As would be released into the environment from cleaning a 18.6-m²-deck. Estimated As doses in children aged 1–6 after 1 h of playing on a wet CCA-wood deck were 0.25–0.41 μg/kg. This is the first study to identify increased dislodgeable As on wet CCA-wood and to evaluate dislodgeable CrVI after bleach application. Our data suggest that As and CrVI in 25-year old CCA-wood still show exposure risks for children and potential for soil contamination.     

Exposure to long-term air pollution and road traffic noise in relation to cholesterol: A cross-sectional study

BackgroundExposure to traffic noise and air pollution have both been associated with cardiovascular disease, though the mechanisms behind are not yet clear.ObjectivesWe aimed to investigate whether the two exposures were associated with levels of cholesterol in a cross-sectional design.MethodsIn 1993–1997, 39,863 participants aged 50–64 year and living in the Greater Copenhagen area were enrolled in a population-based cohort study. For each participant, non-fasting total cholesterol was determined in whole blood samples on the day of enrolment. Residential addresses 5-years preceding enrolment were identified in a national register and road traffic noise (L_den) were modeled for all addresses. For air pollution, nitrogen dioxide (NO₂) was modeled at all addresses using a dispersion model and PM_2.5 was modeled at all enrolment addresses using a land-use regression model. Analyses were done using linear regression with adjustment for potential confounders as well as mutual adjustment for the three exposures.ResultsBaseline residential exposure to the interquartile range of road traffic noise, NO₂ and PM_2.5 was associated with a 0.58 mg/dl (95% confidence interval: − 0.09; 1.25), a 0.68 mg/dl (0.22; 1.16) and a 0.78 mg/dl (0.22; 1.34) higher level of total cholesterol in single pollutant models, respectively. In two pollutant models with adjustment for noise in air pollution models and vice versa, the association between air pollution and cholesterol remained for both air pollution variables (NO₂: 0.72 (0.11; 1.34); PM_2.5: 0.70 (0.12; 1.28) mg/dl), whereas there was no association for noise (− 0.08 mg/dl). In three-pollutant models (NO₂, PM_2.5 and road traffic noise), estimates for NO₂ and PM_2.5 were slightly diminished (NO₂: 0.58 (− 0.05; 1.22); PM_2.5: 0.57 (− 0.02; 1.17) mg/dl).ConclusionsAir pollution and possibly also road traffic noise may be associated with slightly higher levels of cholesterol, though associations for the two exposures were difficult to separate.