Non-specific physical symptoms and electromagnetic field exposure in the general population: Can we get more specific? A systematic review

ObjectiveA systematic review of observational studies was performed to address the strength of evidence for an association between actual and perceived exposure to electromagnetic fields (EMF) and non-specific physical symptoms (NSPS) in the general population. To gain more insight into the magnitude of a possible association, meta-analyses were conducted.MethodsLiterature databases Medline, Embase, SciSearch, PsychInfo, Psyndex and Biosis and additional bibliographic sources such as reference sections of key publications were searched for the detection of studies published between January 2000 and April 2011.ResultsTwenty-two studies met our inclusion criteria. Qualitative assessment of the epidemiological evidence showed either no association between symptoms and higher EMF exposure or contradictory results. To strengthen our conclusions, random effects meta-analyses were performed, which produced the following results for the association with actual EMF; for symptom severity: Headache odds ratio (OR) = 1.65; 95% confidence interval (CI) = 0.88–3.08, concentration problems OR = 1.28; 95% CI = 0.56–2.94, fatigue-related problems OR = 1.15; 95% CI = 0.59–2.27, dizziness-related problems OR = 1.38; 95% CI = 0.92–2.07. For symptom frequency: headache OR = 1.01; 95% CI = 0.66–1.53, fatigue OR = 1.12; 95% CI = 0.60–2.07 and sleep problems OR = 1.18; 95% CI = 0.80–1.74. Associations between perceived exposure and NSPS were more consistently observed but a meta-analysis was not performed due to considerable heterogeneity between the studies.ConclusionsThis systematic review and meta-analysis finds no evidence for a direct association between frequency and severity of NSPS and higher levels of EMF exposure. An association with perceived exposure seems to exist, but evidence is still limited because of differences in conceptualization and assessment methods.     

Road-traffic noise and factors influencing noise annoyance in an urban population

Noise annoyance is influenced by sound-related factors: type of noise, noise level and frequency, and person-related factors—physiological, psychological, and social factors. Prior to implementation of the Directive 2002/49/EC of the European Parliament and of the Council in Serbia, there was a need for the first comprehensive study on noise annoyance in Serbian urban population. The aim of this study was to determine principal factors for high noise annoyance in an adult urban population and to assess their predictive value. A cross-sectional study was performed on 3097 adult residents of a downtown municipality in Belgrade (1217 men and 1880 women), aged 18–96 years. Equivalent noise levels [Leq (dBA)] were measured during day, evening and night in all streets of the municipality. Noise annoyance was estimated using self-reported annoyance scale. Noise annoyance showed strong correlation with noise levels, personal characteristics and some housing conditions. Dose–response relationship was found between the percentage of highly annoyed residents and Lden. Logistic regression model identified increased risk for a high level of noise annoyance with regard to: orientation of living room/bedroom toward the street (Odds Ratio = 2.60; 95% Confidence Interval = 2.04–3.31), duration of stay at apartment during the day [OR = 1.04, 95%CI = 1.02–1.06 (per hour)], noise sensitivity [OR = 1.04, 95%CI = 1.03–1.04 (per scale unit)], and nighttime road-traffic noise level [OR = 1.03, 95%CI = 1.02–1.04 (per decibel)].     

Exposure to multiple sources of polycyclic aromatic hydrocarbons and breast cancer incidence

BackgroundDespite studies having consistently linked exposure to single-source polycyclic aromatic hydrocarbons (PAHs) to breast cancer, it is unclear whether single sources or specific groups of PAH sources should be targeted for breast cancer risk reduction.ObjectivesThis study considers the impact on breast cancer incidence from multiple PAH exposure sources in a single model, which better reflects exposure to these complex mixtures.MethodsIn a population-based case-control study conducted on Long Island, New York (N = 1508 breast cancer cases/1556 controls), a Bayesian hierarchical regression approach was used to estimate adjusted posterior means and credible intervals (CrI) for the adjusted odds ratios (ORs) for PAH exposure sources, considered singly and as groups: active smoking; residential environmental tobacco smoke (ETS); indoor and outdoor air pollution; and grilled/smoked meat intake.ResultsMost women were exposed to PAHs from multiple sources, and the most common included active/passive smoking and grilled/smoked food intake. In multiple-PAH source models, breast cancer incidence was associated with residential ETS from a spouse (OR = 1.20, 95%CrI = 1.03, 1.40) and synthetic firelog burning (OR = 1.29, 95%CrI = 1.06, 1.57); these estimates are similar, but slightly attenuated, to those from single-source models. Additionally when we considered PAH exposure groups, the most pronounced significant associations included total indoor sources (active smoking, ETS from spouse, grilled/smoked meat intake, stove/fireplace use, OR = 1.45, 95%CrI = 1.02, 2.04).ConclusionsGroups of PAH sources, particularly indoor sources, were associated with a 30–50% increase in breast cancer incidence. PAH exposure is ubiquitous and a potentially modifiable breast cancer risk factor.     

Quantifying the impact of traffic-related air pollution on the indoor air quality of a naturally ventilated building

Improper natural ventilation practices may deteriorate indoor air quality when in close proximity to roadways, although the intention is often to reduce energy consumption. In this study, we employed a CFD-based air quality model to quantify the impact of traffic-related air pollution on the indoor air quality of a naturally ventilated building. Our study found that the building envelope restricts dispersion and dilution of particulate matter. The indoor concentration in the baseline condition located 10 m away from the roadway is roughly 16–21% greater than that at the edge of the roadway. The indoor flow recirculation creates a well-mixed zone with little variation in fine particle concentration (i.e., 253 nm). For ultrafine particles (< 100 nm), a noticeable decrease in particle concentrations indoors with increasing distance from the road is observed due to Brownian and turbulent diffusion. In addition, the indoor concentration strongly depends on the distance between the roadway and building, particle size, wind condition, and window size and location. A break-even point is observed at D′ ~ 2.1 (normalized distance from the roadway by the width of the road). The indoor particle concentration is greater than that at the highway where D′ < 2.1, and vice versa. For new building planning, the distance from the roadway and the ambient wind condition need to be considered at the early design stage whereas the size and location of the window openings, the interior layout, and the placement of fresh air intakes are important to the indoor air quality of existing buildings adjacent to roadways.     

Serum and follicular fluid concentrations of polybrominated diphenyl ethers and in-vitro fertilization outcome

There is evidence of endocrine disruption and reproductive effects in animals following exposure to certain PBDEs, but human studies are limited. The goal of this study was to investigate the use of serum and follicular fluid as biomarkers of exposure to PBDEs and to explore whether a relationship between PBDE exposure and early pregnancy loss exists. We measured 8 PBDE congeners in archived serum and ovarian follicular fluid samples from 65 women undergoing in-vitro fertilization (IVF). Logistic regression models were used to predict the odds of failed embryo implantation associated with higher levels of PBDEs among the women in the study. There were moderate Kendall's Tau-beta correlations between serum and follicular fluid concentrations of BDE 28, 47, 100 and 154 (T_β = 0.29–0.38, all p-values < 0.005), but BDE 99 and 153 were not correlated between the two matrices (T_β < 0.2, p-values > 0.05). Women with detectable concentrations of BDE 153 (39% had detectable levels) in follicular fluid had elevated odds of failed implantation compared with women who had non-detectable concentrations (adjusted OR = 10.0; 95%CI: 1.9 to 52; p = 0.006; adjusted by age and body mass index). These findings suggest that exposure to BDE 153 may be associated with failed embryo implantation. Due to our observation of only moderate correlations between matrices, serum PBDE concentrations may not be a good indicator of follicular fluid concentrations when studying early pregnancy endpoints in women undergoing IVF.     

Farm residence and reproductive health among boys in rural South Africa

BackgroundFew studies have investigated reproductive health effects of contemporary agricultural pesticides in boys.ObjectivesTo determine the association between pesticide exposure and reproductive health of boys.MethodsWe conducted a cross-sectional study in rural South Africa of boys living on and off farms. The study included a questionnaire (demographics, general and reproductive health, phyto-estrogen intake, residential history, pesticide exposures, exposures during pregnancy); and a physical examination that included sexual maturity development ratings; testicular volume; height, weight, body mass index; and sex hormone concentrations.ResultsAmong the 269 boys recruited into the study, 177 (65.8%) were categorized as farm (high pesticide exposures) and 98 (34.2%) as non-farm residents (lower pesticide exposures). Median ages of the two groups were 11.3 vs 12.0 years, respectively (p < 0.05). After controlling for confounders that included socioeconomic status, farm boys were shorter (regression coefficient (RC) = − 3.42 cm; 95% confidence interval (CI): − 6.38 to − 0.45 cm) and weighed less (RC = − 2.26 kg; CI: − 4.44 to − 0.75 kg). The farm boys also had lower serum lutenizing hormone (RC = − 0.28 IU/L; CI: − 0.48 to − 0.08 IU/L), but higher serum oestradiol (RC = 8.07 pmol/L; CI: 2.34–13.81 pmol/L) and follicle stimulating hormone (RC = 0.63 IU/L; CI: 0.19–1.08 U/L).ConclusionsOur study provides evidence that farm residence is associated with adverse growth and reproductive health of pubertal boys which may be due to environmental exposures to hormonally active contemporary agricultural pesticides.     

Associations between maternal exposure to air pollution and traffic noise and newborn's size at birth: A cohort study

BackgroundMaternal exposure to air pollution and traffic noise has been suggested to impair fetal growth, but studies have reported inconsistent findings.ObjectiveTo investigate associations between residential air pollution and traffic noise during pregnancy and newborn's size at birth.MethodsFrom a national birth cohort we identified 75,166 live-born singletons born at term with information on the children's size at birth. Residential address history from conception until birth was collected and air pollution (NO₂ and NO_x) and road traffic noise was modeled at all addresses. Associations between exposures and indicators of newborn's size at birth: birth weight, placental weight and head and abdominal circumference were analyzed by linear and logistic regression, and adjusted for potential confounders.ResultsIn mutually adjusted models we found a 10 μg/m³ higher time-weighted mean exposure to NO₂ during pregnancy to be associated with a 0.35 mm smaller head circumference (95% confidence interval (CI): 95% CI: − 0.57; − 0.12); a 0.50 mm smaller abdominal circumference (95% CI: − 0.80; − 0.20) and a 5.02 g higher placental weight (95% CI: 2.93; 7.11). No associations were found between air pollution and birth weight. Exposure to residential road traffic noise was weakly associated with reduced head circumference, whereas none of the other newborn's size indicators were associated with noise, neither before nor after adjustment for air pollution.ConclusionsThis study indicates that air pollution may result in a small reduction in offspring's birth head and abdominal circumference, but not birth weight, whereas traffic noise seems not to affect newborn's size at birth.     

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.     

Urinary concentrations of organophosphate and carbamate pesticides in residents of a vegetarian community

Few population studies have measured urinary levels of pesticides in individuals with vegan, vegetarian, or organic diets. The objectives of this study were to evaluate whether a vegan/vegetarian diet was associated with increased exposure to organophosphate and carbamate pesticides, and to evaluate the impact of organic consumption on pesticide exposure in vegans and vegetarians. In the current pilot study conducted in 2013–2014, we collected spot urine samples and detailed 24 h recall dietary data in 42 adult residents of Amirim, a vegetarian community in Northern Israel. We measured urinary levels of non-specific organophosphate pesticide metabolites (dialkylphosphates, (DAPs)) and specific metabolites of the current-use pesticides chlorpyrifos (3,5,6-trichloro-2-pyridinol (TCPy)), propoxur (-isopropoxyphenol (IPPX)), and carbaryl (1-naphthol). Six DAP metabolites were detected in between 67 and 100% of urine samples, with highest geometric mean concentrations for dimethylphosphate (19.2 μg/g). Creatinine-adjusted median concentrations of total DAPs and of TCPy were significantly higher in Amirim residents compared to the general Jewish population in Israel (0.29 μmol/g compared to 0.16, p < 0.05 for DAPs and 4.32 μg/g compared to 2.34 μg/g, p < 0.05 for TCPy). Within Amirim residents, we observed a positive association between vegetable intake and urinary TCPy levels (rho = 0.47, p < 0.05) and lower median total dimethyl phosphate levels in individuals reporting that > 25% of the produce they consume is organic (0.065 μmol/L compared to 0.22, p < 0.05). Results from this pilot study indicate relatively high levels of urinary organophosphate pesticide metabolite concentrations in residents of a vegetarian community, a positive association between vegetable intake and urinary levels of a chlorpyrifos specific metabolite, and lower levels of total dimethyl phosphate in individuals reporting higher intake of organic produce. Results suggest that consumption of organic produce may offer some protection from increased exposure to organophosphate pesticide residues in vegetarians.     

Could exposure to phthalates speed up or delay pubertal onset and development? A 1.5-year follow-up of a school-based population

PurposePhthalates may interfere with the timing of pubertal development in adolescence and existing studies have shown inconsistent results. This study aims to assess the associations of pubertal onset and progression with urinary concentrations of phthalate metabolites in school-aged boys and girls.MethodsUsing isotope-dilution liquid chromatography tandem mass spectrometry, we analyzed 6 phthalate metabolites in urine samples of 430 children (222 boys and 208 girls) aged 9.7 ± 2.2 years (age range 6.1 to 13.8 years) at baseline and 18 months of follow-up. The associations of exposures to phthalates with pubertal development such as the testis, breast and pubic hair were evaluated using ordered logistic regression models, adjusting for baseline development stage, current chronological age, current body fat composition, and parental education.ResultsUrinary mono-n-butyl phthalate (MnBP) was associated with a 39% increase in the odds of presenting lower pubic hair development stages in boys, and mono (2-ethylhexyl) phthalate (MEHP) (p < 0.10), mono (2-ethyl-5-hydroxyhexyl) phthalate (MEHHP) and mono (2-ethyl-5-oxohexyl) phthalate (MEOHP) were associated with 54%–65% increase in the odds of presenting higher breast development stages in girls (p < 0.05), while MEHHP and MEOHP were also associated with a 70% increase in the odds of menarche onset (p < 0.05). After adjusting for potential confounding variables, the associations of girls' pubertal onset with MnBP, MMP, MEP and MEHP were significant. The odds of girls' breast onset were 4 to 10 times higher in high MnBP, MMP, MEP or MEHP exposure group than in low exposure group.ConclusionsOur findings suggest subtle effects of phthalate metabolites associated with pubertal onset and progression. MnBP exposure may be associated with delayed pubic hair development in boys, while MnBP, MMP, MEP, and MEHP exposures may be associated with breast onset, and MEHP metabolites associated with speedup in breast development progression and earlier menarche onset in girls.     

The national trend of blood lead levels among Chinese children aged 0–18 years old, 1990–2012

We analyzed the epidemiological data during 1990–2012 that investigated the blood lead level (BLL) in the population aged 0–18 years old in China mainland and provided evidence of the benefits of implementing policies to prevent lead pollution based on the dynamic changes of BLL. Data were collected through databases including China Knowledge Resource Integrated Database (CNKI), CBM disc, Wanfang Data, Pubmed and Medline. The inclusion criteria were: 1. Epidemiological study in healthy population not included studies limited to specific patient; 2. Study subject was not the specific lead exposure population; 3. Sample size should be no less than 100 (for neonatal, no less than 50); 4. BLL detection was under strict quality control; and 5. Results should be presented as BLL (arithmetic mean level or geometric mean level). 62 articles were included in this study. All the surveys in these articles contained 189,352 subjects in 19 provinces, autonomous regions and municipalities. Linear regression analysis showed a significant decrease between 1990 and 2012 with an estimated regression coefficient of 3.05/year (SE = 0.01, p < 0.001). BLL gradually declined since early 21st century. Median levels of BLL among the three economic zones were 51.4 μg/L in the eastern zone, 52.72 μg/L in the central zone and 46.2 μg/L in the western zone respectively. Median BLLs in male and female population aged 0–18 years old of China were 48.8 μg/L and 46.1 μg/L. Median levels of BLL among the different age ranges were 74.9 μg/L in newborn, 46.4 μg/L in 0 to 3 years old, 57.6 μg/L in 3 to 7 years old and 55.6 μg/L in above 7 years old respectively. In conclusion, the BLL in the Chinese population of 0–18 years old has gradually dropped in the past 10 years. The decline in temporal trend still remains under potential impacts of several factors such as economical level, gender and age difference. Although, China has made significant achievements in the control prevention of lead pollution, concerted efforts are still warranted to reduce children lead poisoning.     

Occupational exposure to pesticides and Parkinson's disease: A systematic review and meta-analysis of cohort studies

ObjectivesTo systematically review available cohort studies and estimate quantitatively the association between occupational exposure to pesticides and Parkinson's disease (PD).MethodsStudies were identified from a MEDLINE search through 30 November 2011 and from the reference lists of identified publications. Relative risk (RR) estimates were extracted from 12 studies published between 1985 and 2011. Meta-rate ratio estimates (mRR) were calculated according to fixed and random-effect meta-analysis models. Meta-analyses were performed on the whole set of data and separate analyses were conducted after stratification for gender, exposure characterisation, PD cases identification, geographic location, reported risk estimator and cohort study design.ResultsA statistically significant increased risk of PD was observed when all studies were combined (mRR = 1.28; 95% confidence interval [CI]: 1.03–1.59) but there was a high heterogeneity and inconsistency among studies. The highest increased risks were observed for studies with the best design, i.e. reporting PD diagnosis confirmed by a neurologist (mRR = 2.56; CI: 1.46–4.48; n = 4), for cohort studies reporting incidence of PD (mRR = 1.95; CI: 1.29–2.97; n = 3) as well as for prospective cohorts (mRR = 1.39; CI: 1.09–1.78; n = 6). A significant increased risk was also seen for banana, sugarcane and pineapple plantation workers (mRR = 2.05; CI: 1.23–3.42; n = 2).ConclusionsThe present study provides some support for the hypothesis that occupational exposure to pesticides increases the risk of PD.     

Exposure to phthalates,bisphenol A and metals in pregnancy and the association with impaired glucose tolerance and gestational diabetes mellitus: The MIREC study

BackgroundStudies from several countries report increases in rates of gestational diabetes mellitus (GDM) over recent decades. Exposure to environmental chemicals could contribute to this trend.ObjectivesTo determine the associations between plasticisers and metals measured in early pregnancy with impaired glucose tolerance (IGT) and GDM in a Canadian pregnancy cohort.MethodsWomen enrolled in the Maternal–Infant Research on Environmental Chemicals (MIREC) Study were included if they had a singleton delivery and did not have pre-existing diabetes. Eleven phthalate metabolites and total bisphenol A (BPA) were measured in first-trimester urine samples, and four metals (lead, cadmium, mercury and arsenic) were measured in first-trimester blood samples. IGT and GDM were assessed in accordance with standard guidelines by chart review. Chemical concentrations were grouped by quartiles, and associations with outcomes were examined using logistic regression with adjustment for maternal age, race, pre-pregnancy BMI, and education. Restricted cubic spline analysis was performed to help assess linearity and nature of any dose–response relationships.ResultsOf 2001 women recruited into the MIREC cohort, 1274 met the inclusion criteria and had outcome data and biomonitoring data measured for at least one of the chemicals we examined. Elevated odds of GDM were observed in the highest quartile of arsenic exposure (OR = 3.7, 95% CI = 1.4–9.6) in the adjusted analyses. A significant dose–response relationship was observed in a cubic spline model between arsenic and odds of GDM (p < 0.01). No statistically significant associations were observed between phthalates or BPA or other metals with IGT or GDM.ConclusionsOur findings add to the growing body of evidence supporting the role of maternal arsenic exposure as a risk factor for gestational diabetes.     

Predictors of exposure to organophosphate pesticides in schoolchildren in the Province of Talca,Chile

BackgroundFew data exist in Latin America concerning the association between organophosphate (OP) urinary metabolites and the consumption of fruits and vegetables and other exposure risk variables in schoolchildren.MethodsWe collected samples of urine from 190 Chilean children aged 6–12 years, fruits and vegetables, water and soil from schools and homes, and sociodemographic data through a questionnaire. We measured urinary dialkylphosphate (DAP) OP metabolites and OP pesticide residues in food consumed by these 190 children during two seasons: December 2010 (summer) and May 2011 (fall). We analyzed the relationship between urinary DAP concentrations and pesticide residues in food, home pesticide use, and residential location.ResultsDiethylalkylphosphates (DEAP) and dimethylalkylphosphates (DMAP) were detected in urine in 76% and 27% of the samples, respectively. Factors associated with urinary DEAP included chlorpyrifos in consumed fruits (p < 0.0001), urinary creatinine (p < 0.0001), rural residence (p = 0.02) and age less than 9 years (p = 0.004). Factors associated with urinary DMAP included the presence of phosmet residues in fruits (p < 0.0001), close proximity to a farm (p = 0.002), home fenitrothion use (p = 0.009), and season (p < 0.0001).ConclusionsUrinary DAP levels in Chilean school children were high compared to previously reported studies. The presence of chlorpyrifos and phosmet residues in fruits was the major factor predicting urinary DAP metabolite concentrations in children.     

Modeling of road traffic noise and estimated human exposure in Fulton County,Georgia, USA

Environmental noise is a major source of public complaints. Noise in the community causes physical and socio-economic effects and has been shown to be related to adverse health impacts. Noise, however, has not been actively researched in the United States compared with the European Union countries in recent years. In this research, we aimed at modeling road traffic noise and analyzing human exposure in Fulton County, Georgia, United States. We modeled road traffic noise levels using the United States Department of Transportation Federal Highway Administration Traffic Noise Model implemented in SoundPLAN®. After analyzing noise levels with raster, vector and façade maps, we estimated human exposure to high noise levels. Accurate digital elevation models and building heights were derived from Light Detection And Ranging survey datasets and building footprint boundaries. Traffic datasets were collected from the Georgia Department of Transportation and the Atlanta Regional Commission. Noise level simulation was performed with 62 computers in a distributed computing environment. Finally, the noise-exposed population was calculated using geographic information system techniques. Results show that 48% of the total county population [N = 870,166 residents] is potentially exposed to 55 dB(A) or higher noise levels during daytime. About 9% of the population is potentially exposed to 67 dB(A) or higher noises. At nighttime, 32% of the population is expected to be exposed to noise levels higher than 50 dB(A). This research shows that large-scale traffic noise estimation is possible with the help of various organizations. We believe that this research is a significant stepping stone for analyzing community health associated with noise exposures in the United States.     

Baseline blood trihalomethanes,semen parameters and serum total testosterone: A cross-sectional study in China

Toxicological studies showed that trihalomethanes (THMs), the most abundant classes of disinfection by-products (DBPs) in drinking water, impaired male reproductive health, but epidemiological evidence is limited and inconsistent. This study aimed to examine the associations of baseline blood THMs with semen parameters and serum total testosterone in a Chinese population. We recruited 401 men seeking semen examination from the Reproductive Center of Tongji Hospital in Wuhan, China between April 2011 and May 2012. Baseline blood concentrations of THMs, including chloroform (TCM), bromodichloromethane (BDCM), dibromochloromethane (DBCM), and bromoform (TBM) were measured using SPME-GC/ECD method. Semen quality and serum total testosterone were analyzed. Multivariable linear regressions were used to assess the associations of baseline blood THM concentrations with semen parameters and serum total testosterone levels. We found that baseline blood THM concentrations were not associated with decrements in sperm motility, sperm straight-line and curvilinear velocity. However, moderate levels of BDCM (β = − 0.13 million; 95% CI: − 0.22, − 0.03) and DBCM (β = − 4.74%; 95% CI: − 8.07, − 1.42) were associated with decreased sperm count and declined sperm linearity compared with low levels, respectively. Suggestive dose–response relationships were also observed between elevated blood TCM or ∑ THMs (sum of TCM, BDCM, DBCM and TBM) concentration and decreased sperm concentration (both p for trend = 0.07), and between elevated blood DBCM concentration and decreased serum total testosterone (p for trend = 0.07). Our results indicate that elevated THM exposure may lead to decreased sperm concentration and serum total testosterone. However, the effects of THM exposure on male reproductive health still warrant further studies in humans.     

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.     

Air pollution and hospitalization for acute complications of diabetes in Chile

Exposure to air pollution has been shown to cause insulin resistance in mice. To determine the relevance to humans, we tested the association between daily air pollution concentrations and daily hospitalization for acute serious complications of diabetes, coma and ketoacidosis, in Santiago between 2001 and 2008, using generalized linear models with natural splines to control for long term trends.For an interquartile range (IQR) increase in air pollutant, the relative risks (95% CI) of hospitalization for diabetes were: 1.15 (1.10, 1.20) for carbon monoxide (IQR = 1.00); 1.07 (0.98, 1.16) for ozone (IQR = 63.50); 1.14 (1.06, 1.22) for sulfur dioxide (IQR = 5.88); 1.12(1.05, 1.20) for nitrogen dioxide (IQR = 27.94); 1.11 (1.07, 1.15) for particulate matter ≤ 10 μm diameter(IQR = 34.00); and 1.11 (1.06, 1.16) for fine particulate matter ≤ 2.5 μm diameter (IQR = 18.50). Results were similar when stratified by age, sex and season. Air pollution appears to increase the risk of acute complications of diabetes requiring hospitalization, suggesting that improvements in air quality may reduce morbidity from diabetes.     

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.     

Distribution of persistent organic pollutants in serum,omental, and parietal adipose tissue of French women with deep infiltrating endometriosis and circulating versus stored ratio as new marker of exposure

Several studies have assessed the potential role of environmental chemicals in the onset, growth, and/or physiopathology of endometriosis. However, their contour in terms of considered exposure markers remains limited. The present study aimed to characterize the internal exposure levels of 78 persistent organic pollutants (POPs, including dioxins, polychlorobiphenyls, brominated flame retardants and organochlorine pesticides) in a set of 113 adult French women (45 controls, 68 cases), and to characterize the distribution of these POPs within three biological compartments (omental adipose tissue, parietal adipose tissue, and serum). For all targeted substances, the correlation between the concentrations measured in omental versus parietal adipose tissue was found strongly significant (p < 0.0001). An equivalence of the measures performed in parietal and omental adipose tissue was moreover observed with median levels of 6.4 vs. 7.4 pg/g l.w. for WHO-TEQ₂₀₀₅ PCDD/F, 4.5 vs. 4.7 pg/g l.w. for WHO-TEQ₂₀₀₅ dl-PCB, 137.1 vs. 147.9 ng/g l.w. for sum of 6 ndl-PCB, and 2.1 vs. 2.0 ng/g l.w. for sum of 7 i-PBDE, respectively. The same observation was made for individual targeted OCs compounds. Significant correlations were also observed between these concentrations determined in adipose tissue and those measured in serum for dioxins (WHO-TEQ₂₀₀₅ PCDD/F = 6.1 pg/g l.w), PCBs (WHO-TEQ₂₀₀₅ dl-PCB = 3.6 pg/g l.w., sum of 6 ndl-PCB = 81.1 ng/g l.w.), and brominated flame-retardants (sum of 7 i-PBDE = 0.9 ng/g l.w.). The circulating versus stored ratio of some exposure markers (Sum PCDDs, 1,2,3,6,7,8-HxCDF, slightly versus highly chlorinated PCBs ratio, PBDE 99 and PBB 153) was found statistically different for control and case individuals. These extended exposure data from deep infiltrating endometriosis patients are the first ones available for France and give a new insight about the equilibrium of chemicals between storage and circulating compartments that should be further considered as new marker of exposure in the context of exposure-health relationship studies.