The impact of summer temperatures and heatwaves on mortality and morbidity in Perth,Australia 1994–2008

Climate change projections have drawn attention to the risks of extreme heat and the importance of public health interventions to minimise the impact. The city of Perth, Western Australia, frequently experiences hot summer conditions, with recent summers showing above average temperatures. Daily maximum and minimum temperatures, mortality, emergency department (ED) presentations and hospital admissions data were acquired for Perth for the period 1994 to 2008. Using an observed/expected analysis, the temperature thresholds for mortality were estimated at 34–36 °C (maximum) and 20 °C (minimum). Generalised estimating equations (GEEs) were used to estimate the percentage increase in mortality and morbidity outcomes with a 10 °C increment in temperature, with adjustment for air pollutants. Effect estimates are reported as incidence rate ratios (IRRs). The health impact of heatwave days (three or more days of ≥ 35 °C) was also investigated. A 9.8% increase in daily mortality (IRR 1.098; 95%CI: 1.007–1.196) was associated with a 10 °C increase in maximum temperature above threshold. Total ED presentations increased by 4.4% (IRR 1.044; 95%CI: 1.033–1.054) and renal-related ED presentations by 10.2% (IRR 1.102; 95%CI: 1.071–1.135) per 10 °C increase in maximum temperature. Heatwave days were associated with increases in daily mortality and ED presentations, while total hospital admissions were decreased on heatwave days. Public health interventions will be increasingly important to minimise the adverse health impacts of hot weather in Perth, particularly if the recent trend of rising average temperatures and more hot days continues as projected.     

The short-term effect of heat waves on mortality and its modifiers in China: An analysis from 66 communities

BackgroundMany studies have reported increased mortality risk associated with heat waves. However, few have assessed the health impacts at a nation scale in a developing country. This study examines the mortality effects of heat waves in China and explores whether the effects are modified by individual-level and community-level characteristics.MethodsDaily mortality and meteorological variables from 66 Chinese communities were collected for the period 2006–2011. Heat waves were defined as ≥ 2 consecutive days with mean temperature ≥ 95th percentile of the year-round community-specific distribution. The community-specific mortality effects of heat waves were first estimated using a Distributed Lag Non-linear Model (DLNM), adjusting for potential confounders. To investigate effect modification by individual characteristics (age, gender, cause of death, education level or place of death), separate DLNM models were further fitted. Potential effect modification by community characteristics was examined using a meta-regression analysis.ResultsA total of 5.0% (95% confidence intervals (CI): 2.9%–7.2%) excess deaths were associated with heat waves in 66 Chinese communities, with the highest excess deaths in north China (6.0%, 95% CI: 1%–11.3%), followed by east China (5.2%, 95% CI: 0.4%–10.2%) and south China (4.5%, 95% CI: 1.4%–7.6%). Our results indicate that individual characteristics significantly modified heat waves effects in China, with greater effects on cardiovascular mortality, cerebrovascular mortality, respiratory mortality, the elderly, females, the population dying outside of a hospital and those with a higher education attainment. Heat wave mortality effects were also more pronounced for those living in urban cities or densely populated communities.ConclusionHeat waves significantly increased mortality risk in China with apparent spatial heterogeneity, which was modified by some individual-level and community-level factors. Our findings suggest adaptation plans that target vulnerable populations in susceptible communities during heat wave events should be developed to reduce health risks.     

Comparing exposure metrics for classifying ‘dangerous heat’ in heat wave and health warning systems

Heat waves have been linked to excess mortality and morbidity, and are projected to increase in frequency and intensity with a warming climate. This study compares exposure metrics to trigger heat wave and health warning systems (HHWS), and introduces a novel multi-level hybrid clustering method to identify potential dangerously hot days. Two-level and three-level hybrid clustering analysis as well as common indices used to trigger HHWS, including spatial synoptic classification (SSC), and the 90th, 95th, and 99th percentiles of minimum and relative minimum temperature (using a 10 day reference period), were calculated using a summertime weather dataset in Detroit from 1976 to 2006. The days classified as ‘hot’ with hybrid clustering analysis, SSC, minimum and relative minimum temperature methods differed by method type. SSC tended to include the days with, on average, 2.5 °C lower daily minimum temperature and 5.3 °C lower dew point than days identified by other methods. These metrics were evaluated by comparing their performance in predicting excess daily mortality. The 99th percentile of minimum temperature was generally the most predictive, followed by the three-level hybrid clustering method, the 95th percentile of minimum temperature, SSC and others. Our proposed clustering framework has more flexibility and requires less substantial meteorological prior information than the synoptic classification methods. Comparison of these metrics in predicting excess daily mortality suggests that metrics thought to better characterize physiological heat stress by considering several weather conditions simultaneously may not be the same metrics that are better at predicting heat-related mortality, which has significant implications in HHWSs.     

Association between background exposure to organochlorine pesticides and the risk of cognitive impairment: A prospective study that accounts for weight change

BackgroundBackground exposure to organochlorine (OC) pesticides was recently linked to cognitive impairment and dementia in cross-sectional and case–control studies. This prospective study was performed to evaluate if OC pesticides at baseline are associated with the future risk of cognitive impairment in elderly, with particular focus on weight change.MethodsPlasma concentrations of 3 OC pesticides (p,p′-DDE, trans-nonachlor, and hexachlorobenzene) were measured among 989 men and women aged 70 years in the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS). Cognitive impairment was validated by reviewing medical records. During the ten year follow-up, cognitive impairment was developed in 75 subjects. When weight change from age 70 to 75 was considered in analyses, elderly with incident cases before age 75 were excluded to keep the prospective perspective, leaving 795 study subjects and 44 incident cases.ResultsThe summary measure of 3 OC pesticides predicted the development of cognitive impairment after adjusting for covariates, including weight change. Compared to subjects with OC pesticides < 25th percentile, adjusted hazard ratios (HRs) in those with 25th–<75th and ≥ 75th percentiles were 3.5 (95% confidence interval: 1.5–8.5) and 3.2 (1.1–7.6), respectively (P_trend = 0.04). Among 506 subjects who maintained or gained body weight, adjusted HRs were 6.9 and 11.6 (1.4–92.6) among the elderly in the 25th–<75th and ≥ 75th percentiles compared to < 25th percentile (P_trend < 0.01).ConclusionsThis prospective study demonstrates that background exposure to OC pesticides are linked to the risk of developing cognitive impairment in elderly. The role of the chronic exposure to low dose OC pesticides in the development of dementia should be further evaluated in other populations.     

Background exposure to persistent organic pollutants predicts stroke in the elderly

Background exposure to persistent organic pollutants (POPs), lipophilic xenobiotics that accumulate mainly in adipose tissue, has recently emerged as a new risk factor for cardiovascular diseases. This prospective study was performed to evaluate if plasma concentrations of selected POPs predict incident stroke among the elderly. Twenty‐one POPs (including 16 polychlorinated biphenyl (PCB) congeners, 3 organochlorine (OC) pesticides, 1 brominated diphenyl ether (BDE), and 1 dioxin) were measured in plasma collected at baseline in 898 participants aged 70 years of the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS). Stroke diagnosis was validated by hospital records. During the five year follow-up, 35 subjects developed hospital-treated stroke. After adjusting for known stroke risk factors, most PCBs with 4, 5, or 6 chlorine atoms, p,p′-DDE, trans-nonachlor, and octachlorodibenzo-p-dioxin significantly predicted the risk of stroke. Across quartiles of summary measures of PCBs and OC pesticides, the adjusted ORs were 1.0, 0.8 (95% confidence interval: 0.2–2.5), 1.2 (0.4–3.4), and 2.1 (0.7–6.2) for PCBs and 1.0, 1.2 (0.3–4.2), 2.3 (0.7–6.9), and 3.0 (1.0–9.4) for OC pesticides (P for trend = 0.11 and 0.03, respectively). The adjusted ORs among participants ≥ 90th percentile of the summary measures were 5.5 (1.7–18.1) for PCBs and 4.0 (1.1–14.6) for OC pesticides; corresponding ORs for those ≥ 95th percentile were 7.8 (2.1–29.6) and 9.5 (2.3–38.9). Background exposure to POPs may play an important role in development or progression of stroke in the elderly.     

Saharan dust,particulate matter and cause-specific mortality: A case–crossover study in Barcelona (Spain)

BackgroundStudies measuring health effects of Saharan dust based on large particulate matter (PM) fraction groups may be masking some effects. Long distant transport reduces the amount of heavier and larger particles in the Saharan air masses increasing the relative contribution of smaller particles that may be more innocuous. This study investigates the association between different PM fractions and daily mortality during Saharan and non-Saharan days in Barcelona, Spain.MethodsWe collected daily PM₁, PM_2.5–1 and PM_10–2.5 fractions, and cause-specific mortality (cardiovascular, respiratory and cerebrovascular) between March 2003 and December 2007. Changes of effects between Saharan and non-Saharan dust days were assessed using a time-stratified case–crossover design.ResultsDuring non-Saharan dust days we found statistically significant (p < 0.05) effects of PM_10–2.5 for cardiovascular (odds ratio for increase of an interquartile range, OR = 1.033, 95% confidence interval: 1.006–1.060) and respiratory mortality (OR = 1.044, 95% CI: 1.001–1.089). During Saharan dust days strongest cardiovascular effects were found for the same fraction (OR = 1.085, 95% CI: 1.017–1.158) with an indication of effect modification (p = 0.111). Effects of PM_2.5–1 during Saharan dust days were about the double than in non-dust days for cardiovascular and respiratory mortality, but these differences were not statistically significant.ConclusionOur results using independent fractions of PMs provide further evidence that the effects of short-term exposure to PM during Saharan dust days are associated with both cardiovascular and respiratory mortality. A better understanding of which of the different PM size fractions brought by Saharan dust is more likely to accelerate adverse effects may help better understand mechanisms of toxicity.     

Associations between short/medium-term variations in black smoke air pollution and mortality in the Glasgow conurbation,UK

ObjectivesTo examine associations between short/medium-term variations in black smoke air pollution and mortality in the population of Glasgow and the adjacent towns of Renfrew and Paisley over a 25-year period at different time lags (0–30 days).MethodsGeneralised linear (Poisson) models were used to investigate the relationship between lagged black smoke concentrations and daily mortality, with allowance for confounding by cold temperature, between 1974 and 1998.ResultsWhen a range of lag periods were investigated significant associations were noted between temperature-adjusted black smoke exposure and all-cause mortality at lag periods of 13–18 and 19–24 days, and respiratory mortality at lag periods of 1–6, 7–12, and 13–18 days. Significant associations between cardiovascular mortality and temperature-adjusted black smoke were not observed. After adjusting for the effects of temperature a 10 μg m^− 3 increase in black smoke concentration on a given day was associated with a 0.9% [95% Confidence Interval (CI): 0.3–1.5%] increase in all cause mortality and a 3.1% [95% CI: 1.4–4.9%] increase in respiratory mortality over the ensuing 30-day period. In contrast for a 10 μg m^− 3 increase in black smoke concentration over 0–3 day lag period, the temperature adjusted exposure mortality associations were substantially lower (0.2% [95% CI: − 0.0–0.4%] and 0.3% [95% CI: − 0.2–0.8%] increases for all-cause and respiratory mortality respectively).ConclusionsThis study has provided evidence of association between black smoke exposure and mortality at longer lag periods than have been investigated in the majority of time series analyses.     

Prenatal methylmercury exposure and language delay at three years of age in the Norwegian Mother and Child Cohort Study

Prenatal methylmercury (MeHg) exposure and its possible neurodevelopmental effects in susceptible children are of concern. Studies of MeHg exposure and negative health outcomes have shown conflicting results and it has been suggested that co-exposure to other contaminants and/or nutrients in fish may confound the effect of MeHg. Our objective was to examine the association between prenatal exposure to MeHg and language and communication development at three years, adjusting for intake of fish, n − 3 long chain polyunsaturated fatty acids (n − 3 LCPUFAs) and co-exposure to dioxins and dioxin like polychlorinated biphenyls (dl-PCBs).We used data from the Norwegian Mother and Child Cohort Study (MoBa) collected between 2002 and 2008. The study sample consisted of 46,750 mother-child pairs. MeHg exposure was calculated from reported fish intake during pregnancy by a FFQ in mid-pregnancy. Children's language and communication skills were measured by maternal report on the Dale and Bishop grammar rating and the Ages and Stages communication scale (ASQ). We estimated odds ratios (OR) and 95% confidence intervals (CI) using logistic regressions.Median MeHg exposure was 1.3 μg/day, corresponding to 0.14 μg/kg bw/week. An exposure level above the 90th percentile (> 2.6 μg/day, > 0.29 μg/kg bw/week) was defined as the high MeHg exposure. Results indicated an association between high MeHg exposure and unintelligible speech with an adjusted OR 2.22 (1.31, 3.72). High MeHg exposure was also associated with weaker communication skills adjusted OR 1.33 (1.03, 1.70). Additional adjustment for fish intake strengthened the associations, while adjusting for PCBs and n − 3 LCPUFA from diet or from supplements had minor impact. In conclusion, significant associations were found between prenatal MeHg exposure above the 90th percentile and delayed language and communication skills in a generally low exposed population.     

Health risks caused by short term exposure to ultrafine particles generated by residential wood combustion: A case study of Temuco,Chile

Temuco is one of the most highly wood smoke polluted cities in Chile; however, there is scarce evidence of respiratory morbidity due to fine particulate matter. We aimed to estimate the relationship between daily concentration of ultrafine particles (UFP), with an aerodynamic diameter ≤ 0.1 μm, and outpatient visits for respiratory illness at medical care centers of Temuco, Chile, from August the 20th, 2009 to June the 30th, 2011. The Air Pollution Health Effects European Approach (APHEA2) protocol was followed, and a multivariate semi-parametric Poisson regression model was fitted with GAM techniques using R-Project statistical package; controlling for trend, seasonality, and confounders. The daily UFP were measured by a MOUDI NR-110 sampler. We found that results of the statistical analyses show significant associations between UFP and respiratory outpatient visits, with the elderly (population ≥ 65 years), being the group that presented the greatest risk. An interquartile increase of 4.73 μg/m³ in UFP (lag 5 days) was associated with respiratory outpatient visits with a relative risk (RR) of 1.1458 [95% CI (1.0497–1.2507)] for the elderly. These results show novel findings regarding the relevance of daily UFP concentrations and health risk, especially for susceptible population in a wood smoke polluted city.     

EPA's SHEDS-multimedia model: Children's cumulative pyrethroid exposure estimates and evaluation against NHANES biomarker data

The U.S. EPA's SHEDS-Multimedia model was applied to enhance the understanding of children's exposures and doses to multiple pyrethroid pesticides, including major contributing chemicals and pathways. This paper presents combined dietary and residential exposure estimates and cumulative doses for seven commonly used pyrethroids, and comparisons of model evaluation results with NHANES biomarker data for 3-PBA and DCCA metabolites. Model input distributions were fit to publicly available pesticide usage survey data, NHANES, and other studies, then SHEDS-Multimedia was applied to estimate total pyrethroid exposures and doses for 3–5 year olds for one year variability simulations. For dose estimations we used a pharmacokinetic model and two approaches for simulating dermal absorption. SHEDS-Multimedia predictions compared well to NHANES biomarker data: ratios of 3-PBA observed data to SHEDS-Multimedia modeled results were 0.88, 0.51, 0.54 and 1.02 for mean, median, 95th, and 99th percentiles, respectively; for DCCA, the ratios were 0.82, 0.53, 0.56, and 0.94. Modeled time-averaged cumulative absorbed dose of the seven pyrethroids was 3.1 nmol/day (versus 8.4 nmol/day for adults) in the general population (residential pyrethroid use and non-use homes) and 6.7 nmol/day (versus 10.5 nmol/day for adults) in the simulated residential pyrethroid use population. For the general population, contributions to modeled cumulative dose by chemical were permethrin (60%), cypermethrin (22%), and cyfluthrin (16%); for residential use homes, contributions were cypermethrin (49%), permethrin (29%), and cyfluthrin (17%). The primary exposure route for 3–5 year olds in the simulated residential use population was non-dietary ingestion exposure; whereas for the simulated general population, dietary exposure was the primary exposure route. Below the 95th percentile, the major exposure pathway was dietary for the general population; non-dietary ingestion was the major pathway starting below the 70th percentile for the residential use population. The new dermal absorption methodology considering surface loading had some impact, but did not change the order of key pathways.     

Changing patterns of the temperature–mortality association by time and location in the US,and implications for climate change

The shape of the non-linear relationship between temperature and mortality varies among cities with different climatic conditions. There has been little examination of how these curves change over space and time. We evaluated the short-term effects of hot and cold temperatures on daily mortality over six 7-year periods in 211 US cities, comprising over 42 million deaths. Cluster analysis was used to group the cities according to similar temperatures and relative humidity. Temperature–mortality functions were calculated using B-splines to model the heat effect (lag 0) and the cold effect on mortality (moving average lags 1–5). The functions were then combined through meta-smoothing and subsequently analyzed by meta-regression. We identified eight clusters. At lag 0, Cluster 5 (West Coast) had a RR of 1.14 (95% CI: 1.11,1.17) for temperatures of 27 °C vs 15.6 °C, and Cluster 6 (Gulf Coast) has a RR of 1.04 (95% CI: 1.03,1.05), suggesting that people are acclimated to their respective climates. Controlling for cluster effect in the multivariate-meta regression we found that across the US, the excess mortality from a 24-h temperature of 27 °C decreased over time from 10.6% to 0.9%. We found that the overall risk due to the heat effect is significantly affected by summer temperature mean and air condition usage, which could be a potential predictor in building climate-change scenarios.     

High resolution exposure modelling of heat and air pollution and the impact on mortality

BackgroundElevated temperature and air pollution have been associated with increased mortality. Exposure to heat and air pollution, as well as the density of vulnerable groups varies within cities. The objective was to investigate the extent of neighbourhood differences in mortality risk due to heat and air pollution in a city with a temperate maritime climate.MethodsA case-crossover design was used to study associations between heat, air pollution and mortality. Different thermal indicators and air pollutants (PM₁₀, NO₂, O₃) were reconstructed at high spatial resolution to improve exposure classification. Daily exposures were linked to individual mortality cases over a 15 year period.ResultsSignificant interaction between maximum air temperature (Ta_max) and PM₁₀ was observed. During “summer smog” days (Ta_max > 25 °C and PM₁₀ > 50 μg/m³), the mortality risk at lag 2 was 7% higher compared to the reference (Ta_max 15 °C and PM₁₀ 15 μg/m³). Persons above age 85 living alone were at highest risk.ConclusionWe found significant synergistic effects of high temperatures and air pollution on mortality. Single living elderly were the most vulnerable group. Due to spatial differences in temperature and air pollution, mortality risks varied substantially between neighbourhoods, with a difference up to 7%.     

French children's exposure to metals via ingestion of indoor dust,outdoor playground dust and soil: Contamination data

In addition to dietary exposure, children are exposed to metals via ingestion of soils and indoor dust, contaminated by natural or anthropogenic outdoor and indoor sources. The objective of this nationwide study was to assess metal contamination of soils and dust which young French children are exposed to. A sample of 484 children (6 months to 6 years) was constituted in order to obtain representative results for young French children. In each home indoor settled dust was sampled by a wipe in up to five rooms. Outdoor playgrounds were sampled with a soil sample ring (n = 315) or with a wipe in case of hard surfaces (n = 53). As, Cd, Cr, Cu, Mn, Pb, Sb, Sr, and V were measured because of their potential health concern due to soil and dust ingestion. The samples were digested with hydrochloric acid, and afterwards aqua regia in order to determine both leachable and total metal concentrations and loadings by mass spectrometry with a quadrupole ICP-MS. In indoor settled dust most (total) loadings were below the Limit of Quantification (LOQ), except for Pb and Sr, whose median loadings were respectively 9 and 10 μg/m². The 95th percentile of loadings were 2 μg/m² for As, < 0.8 for Cd, 18 for Cr, 49 for Cu, < 64 for Mn, 63 for Pb, 2 for Sb, 56 for Sr, and < 8 for V. Median/95th percentile of loadings in settled dust on outdoor playgrounds were 2/16, < 0.8/1.3, 17/53, 49/330, 99/424, 32/393, 2/13, 86/661 and 10/37 μg/m² for As, Cd, Cr, Cu, Mn, Pb, Sb, Sr, and V respectively. In outdoor playground soil median/95th percentile of concentrations (μg/g) were 8/26, < 0.65/1, 25/52, < 26/53,391/956, 27/254, 0.7/4, 54/295, 23/57 for As, Cd, Cr, Cu, Mn, Pb, Sb, Sr, and V respectively. These results are comparable with those observed in other countries. Because of their representative nature, we can assess children's exposures to these metals via soil and dust and the associated risks in urban and rural environments. Ratios of leachable/total concentrations and loadings, calculated on > LOQ measurements, differed among metals. To a lesser extent, they were also affected by type of matrix, with (except for Cd) a greater leachability of dust (especially indoor) compared to soils.     

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.     

Associations between ultrafine and fine particles and mortality in five central European cities — Results from the UFIREG study

BackgroundEvidence on health effects of ultrafine particles (UFP) is still limited as they are usually not monitored routinely. The few epidemiological studies on UFP and (cause-specific) mortality so far have reported inconsistent results.ObjectivesThe main objective of the UFIREG project was to investigate the short-term associations between UFP and fine particulate matter (PM) < 2.5 μm (PM_2.5) and daily (cause-specific) mortality in five European Cities. We also examined the effects of PM < 10 μm (PM₁₀) and coarse particles (PM_2.5–10).MethodsUFP (20–100 nm), PM and meteorological data were measured in Dresden and Augsburg (Germany), Prague (Czech Republic), Ljubljana (Slovenia) and Chernivtsi (Ukraine). Daily counts of natural and cardio-respiratory mortality were collected for all five cities. Depending on data availability, the following study periods were chosen: Augsburg and Dresden 2011–2012, Ljubljana and Prague 2012–2013, Chernivtsi 2013–March 2014. The associations between air pollutants and health outcomes were assessed using confounder-adjusted Poisson regression models examining single (lag 0–lag 5) and cumulative lags (lag 0–1, lag 2–5, and lag 0–5). City-specific estimates were pooled using meta-analyses methods.ResultsResults indicated a delayed and prolonged association between UFP and respiratory mortality (9.9% [95%-confidence interval: − 6.3%; 28.8%] increase in association with a 6-day average increase of 2750 particles/cm³ (average interquartile range across all cities)). Cardiovascular mortality increased by 3.0% [− 2.7%; 9.1%] and 4.1% [0.4%; 8.0%] in association with a 12.4 μg/m³ and 4.7 μg/m³ increase in the PM_2.5- and PM_2.5–10-averages of lag 2–5.ConclusionsWe observed positive but not statistically significant associations between prolonged exposures to UFP and respiratory mortality, which were independent of particle mass exposures. Further multi-centre studies are needed investigating several years to produce more precise estimates on health effects of UFP.     

Reduced birth weight in relation to pesticide mixtures detected in cord blood of full-term infants

Previous research has shown that prenatal exposure to pesticides may be associated with decreased fetal growth. The specific pesticides investigated and results reported across studies have been inconsistent, and there is a mounting need for the consideration of mixtures rather than individual agents in studies of health outcomes in relation to environmental exposures. There are also many individual pesticides that have not been investigated in human health studies to date. We conducted a pilot study in rural Zhejiang province, China, measuring 20 non-persistent pesticides (10 insecticides, 6 herbicides, 3 fungicides, and 1 repellant) in umbilical cord blood of 112 full term (> 37 weeks) infants. The pesticides detected with the greatest frequency were diethyltoluamide (DEET) (73%), a repellant, and vinclozolin (49%), a fungicide. The samples had detectable concentrations for a mean of 4.6 pesticides (SD = 1.9) with a maximum of 10. Adjusting for potential confounders, newborn birth weight was inversely associated with the number of pesticides detected in cord blood (p = 0.04); birth weight decreased by a mean of 37.1 g (95% CI, − 72.5 to − 1.8) for each detected pesticide. When assessing relationships by pesticide type, detection of fungicides was also associated with decreased birth weight (adjusted β = − 116 g [95% CI, − 212 to − 19.2]). For individual pesticides analyzed as dichotomous (detect vs. non-detect) variables, only vinclozolin (adjusted β = − 174 g [95% CI, − 312 to − 36.3]) and acetochlor (adjusted β = − 165 g [95% CI, − 325 to − 5.7]) were significantly associated with reduced birth weight. No significant associations were seen between birth weight and individual pesticides assessed as continuous or 3-level ordinal variables. Our findings from this pilot investigation suggest that exposure to fungicides may adversely impact fetal growth. Exposure to mixtures of multiple pesticides is also of concern and should be explored in addition to individual pesticides. Additional research is needed to establish causality and to understand the function and impact of fungicides and pesticide mixtures on fetal development.     

Living near nuclear power plants and thyroid cancer risk: A systematic review and meta-analysis

There has been public concern regarding the safety of residing near nuclear power plants, and the extent of risk for thyroid cancer among adults living near nuclear power plants has not been fully explored. In the present study, a systematic review and meta-analysis of epidemiologic studies was conducted to investigate the association between living near nuclear power plants and the risk of thyroid cancer. A comprehensive literature search was performed on studies published up to March 2015 on the association between nuclear power plants and thyroid cancer risk. The summary standardized incidence ratio (SIR), standardized mortality ratio (SMR), and 95% confidence intervals (CIs) were calculated using a random-effect model of meta-analysis. Sensitivity analyses were performed by study quality. Thirteen studies were included in the meta-analysis, covering 36 nuclear power stations in 10 countries. Overall, summary estimates showed no significant increased thyroid cancer incidence or mortality among residents living near nuclear power plants (summary SIR = 0.98; 95% CI 0.87–1.11, summary SMR = 0.80; 95% CI 0.62–1.04). The pooled estimates did not reveal different patterns of risk by gender, exposure definition, or reference population. However, sensitivity analysis by exposure definition showed that living less than 20 km from nuclear power plants was associated with a significant increase in the risk of thyroid cancer in well-designed studies (summary OR = 1.75; 95% CI 1.17–2.64). Our study does not support an association between living near nuclear power plants and risk of thyroid cancer but does support a need for well-designed future studies.     

Health burdens of surface ozone in the UK for a range of future scenarios

Exposure to surface ozone (O₃), which is influenced by emissions of precursor chemical species, meteorology and population distribution, is associated with excess mortality and respiratory morbidity. In this study, the EMEP-WRF atmospheric chemistry transport model was used to simulate surface O₃ concentrations at 5 km horizontal resolution over the British Isles for a baseline year of 2003, for three anthropogenic emissions scenarios for 2030, and for a + 5 °C increase in air temperature on the 2003 baseline. Deaths brought forward and hospitalisation burdens for 12 UK regions were calculated from population-weighted daily maximum 8-hour O₃. The magnitude of changes in annual mean surface O₃ over the UK for + 5 °C temperature (+ 1.0 to + 1.5 ppbv, depending on region) was comparable to those due to inter-annual meteorological variability (− 1.5 to + 1.5 ppbv) but considerably less than changes due to precursor emissions changes by 2030 (− 3.0 to + 3.5 ppbv, depending on scenario and region). Including population changes in 2030, both the ‘current legislation’ and ‘maximum feasible reduction’ scenarios yield greater O₃-attributable health burdens than the ‘high’ emission scenario: + 28%, + 22%, and + 16%, respectively, above 2003 baseline deaths brought forward (11,500) and respiratory hospital admissions (30,700), using O₃ exposure over the full year and no threshold for health effects. The health burdens are greatest under the ‘current legislation’ scenario because O₃ concentrations increase as a result of both increases in background O₃ concentration and decreases in UK NO_x emissions. For the + 5 °C scenario, and no threshold (and not including population increases), total UK health burden increases by 500 premature deaths (4%) relative to the 2003 baseline. If a 35 ppbv threshold for O₃ effects is assumed, health burdens are more sensitive to the current legislation and + 5 °C scenarios, although total health burdens are roughly an order of magnitude lower. In all scenarios, the assumption of a threshold increases the proportion of health burden in the south and east of the UK compared with the no threshold assumption. The study highlights that the total, and geographically-apportioned, O₃-attributable health burdens in the UK are highly sensitive to the future trends of hemispheric, regional and local emissions of O₃ precursors, and to the assumption of a threshold for O₃ effect.     

Occurrence of parabens in foodstuffs from China and its implications for human dietary exposure

Parabens are alkyl esters of p-hydroxybenzoic acid and are used as antimicrobial preservatives in a range of consumer products, including cosmetics, pharmaceuticals, and foodstuffs. Despite their widespread use, prior to this study, paraben concentrations in foodstuffs from China and human dietary exposure to these chemicals have been unknown. In this study, concentrations of six parabens were determined in 13 categories of food samples (n = 282), including cereals and cereal products, meat, fish and seafood, eggs, dairy products, bean products, fruits, vegetables, cookies, beverages, cooking oils, condiments, and others, collected from nine cities in China. Almost all (detection rate: 99%) food samples contained at least one of the parabens analyzed, and the total concentrations (ΣParabens; sum of six parabens) ranged from below limit of quantification (LOQ) to 2530 ng/g fresh weight, with an overall mean value of 39.3 ng/g. Methyl paraben (MeP), ethyl paraben (EtP), and propyl paraben (PrP) were the major paraben analogs found in foodstuffs, and these compounds accounted for 59%, 24%, and 10%, respectively, of ΣParaben concentrations. Although the mean concentrations of ΣParabens varied among different categories of food items (from 0.839 ng/g in beverages to 100 ng/g in vegetables), the concentrations were not statistically significant among the 13 food categories, including canned foodstuffs. Estimated daily intake (EDI) of parabens was based on the measured concentrations in foods and the corresponding daily food ingestion rates. The mean and 95th percentile values for EDI were 1010 and 3040 ng/kg body weight (bw)/day for adult men and 1060 and 3170 ng/kg bw/day for adult women, respectively.     

Aggregate consumer exposure to UV filter ethylhexyl methoxycinnamate via personal care products

Ultraviolet (UV) filters are substances designed to protect our skin from UV-induced damage and can be found in many categories of personal care products (PCPs). The potential endocrine-disrupting effects attributed to UV filter ethylhexyl methoxycinnamate (EHMC) are being debated. We evaluated the aggregate exposure of the Swiss–German population (N = 1196; ages ≤ 1–97 years) to EHMC via the use of PCPs; thus we provide the first comprehensive information about the current EHMC exposure sources and aggregate exposure levels. In our probabilistic modeling method performed at an individual level, PCP use data obtained by a postal questionnaire were linked to concentration data on EHMC gained from chemical analyses of PCPs used by the questionnaire respondents. The modeled median and 99.9th percentile of the internal aggregate exposure for the general population were 0.012 and 0.873 mg day^− 1 kg^− 1 and 0.008 and 0.122 mg day^− 1 kg^− 1 for the summer/autumn and winter/spring period, respectively. The major contributors to internal aggregate exposure were sunscreen products in summer/autumn (females: 64%; males: 85%; children aged ≤ 12 years 93%). In winter/spring, lip care dominated for females (30%) and sunscreen for males (38%) and children aged ≤ 12 years (50%). Overall, the internal aggregate exposure estimates for the studied population are shown to be below the Derived No Effect Level (DNEL) for EHMC i.e., the level of exposure above which humans should not be exposed; however, when an intense short-term exposure via sunscreen is accounted for during a sunbathing day, at the high-end percentiles (99.9th) the predicted aggregate exposure exceeds the DNEL for thyroid-disrupting effects such as for children aged ≤ 4 years, who might be particularly susceptible to endocrine disrupting events. It is nevertheless critical to acknowledge that quantitative data on transdermal penetration of EHMC from PCPs are currently insufficient. Since long-term effects of endocrine disruptors are not known, future studies are warranted to provide accurate quantitative data on transdermal penetration of EHMC and to determine its metabolic fate in humans.