Blood persistent organochlorine pesticides in pregnant women in relation to physical and environmental variables in The Hokkaido Study on Environment and Children's Health

Prenatal exposure to pesticides and domain-specific neurodevelopment at age 12 and 18 months in Nanjing, China

BACKGROUND

The extensive usage of pesticides has led to a ubiquitous exposure in the Chinese general population. Previous studies have demonstrated developmental neurotoxicity associated with prenatal exposure to pesticides.

OBJECTIVES

We aimed to delineate the landscape of internal pesticides exposure levels from pregnant women's blood serum samples, and to identify the specific pesticides associated with the domain-specific neuropsychological development.

METHODS

Participants included 710 mother-child pairs in a prospective cohort study initiated and maintained in Nanjing Maternity and Child Health Care Hospital. Maternal spot blood samples were collected at enrollment. Leveraging on an accurate, sensitive and reproducible analysis method for 88 pesticides, a total of 49 pesticides were measured simultaneously using gas chromatography-triple quadrupole tandem mass spectrometry (GC-MS/MS). After implementing a strict quality control (QC) management, 29 pesticides were reported. We assessed neuropsychological development in 12-month-old (n = 172) and 18-month-old (n = 138) children using the Ages and Stages Questionnaire (ASQ), Third Edition. Negative binomial regression models were used to investigate the associations between prenatal exposure to pesticides and ASQ domain-specific scores at age 12 and 18 months. Restricted cubic spline (RCS) analysis and generalized additive models (GAMs) were fitted to evaluate non-linear patterns. Longitudinal models with generalized estimating equations (GEE) were conducted to account for correlations among repeated observations. Weighted quantile sum (WQS) regression and Bayesian kernel machine regression (BKMR) were applied to examining the joint effect of the mixture of pesticides. Several sensitivity analyses were performed to assess the robustness of the results.

RESULTS

We observed that prenatal exposure to chlorpyrifos was significantly associated with a 4 % decrease in the ASQ communication scores both at age 12 months (RR, 0.96; 95 % CI, 0.94-0.98; P < 0.001) and 18 months (RR, 0.96; 95 % CI, 0.93-0.99; P < 0.01). In the ASQ gross motor domain, higher concentrations of mirex (RR, 0.96; 95 % CI, 0.94-0.99, P < 0.01 for 12-month-old children; RR, 0.98; 95 % CI, 0.97-1.00, P = 0.01 for 18-month-old children), and atrazine (RR, 0.97; 95 % CI, 0.95-0.99, P < 0.01 for 12-month-old children; RR, 0.99; 95 % CI, 0.97-1.00, P = 0.03 for 18-month-old children) were associated with decreased scores. In the ASQ fine motor domain, higher concentrations of mirex (RR, 0.98; 95 % CI, 0.96-1.00, P = 0.04 for 12-month-old children; RR, 0.98; 95 % CI, 0.96-0.99, P < 0.01 for 18-month-old children), atrazine (RR, 0.97; 95 % CI, 0.95-0.99, P < 0.001 for 12-month-old children; RR, 0.98; 95 % CI, 0.97-1.00, P = 0.01 for 18-month-old children), and dimethipin (RR, 0.94; 95 % CI, 0.89-1.00, P = 0.04 for 12-month-old children; RR, 0.93; 95 % CI, 0.88-0.98, P < 0.01 for 18-month-old children) were associated with decreased scores. The associations were not modified by child sex. There was no evidence of statistically significant nonlinear relationships between pesticides exposure and RRs of delayed neurodevelopment (P_nonlinearity > 0.05). Longitudinal analyses implicated the consistent findings.

CONCLUSION

This study gave an integrated picture of pesticides exposure in Chinese pregnant women. We found significant inverse associations between prenatal exposure to chlorpyrifos, mirex, atrazine, dimethipin and the domain-specific neuropsychological development (i.e., communication, gross motor and fine motor) of children at 12 and 18 months of age. These findings identified specific pesticides with high risk of neurotoxicity, and highlighted the need for priority regulation of them.

Persistent organochlorine pesticides in periprostatic adipose tissue from men with prostate cancer: Ethno-geographic variations, association with disease aggressiveness

Although several studies have examined the relationship between organochlorine pesticides (OCPs) and prostate cancer (PCa) risk, no data are available concerning the association between OCPs concentrations in periprostatic adipose tissue (PPAT), which reflects cumulative exposure, and PCa aggressiveness. Moreover, no previous study has compared OCPs exposure in two distinct ethno-geographical populations. The objectives were to analyze OCPs in PPAT of PCa patients from either Mainland France or French West Indies in correlation with features of tumor aggressiveness, after adjusting for potential confounders such age, BMI, and polyunsaturated fatty acid (PUFA) content of PPAT. PPAT was analyzed in 160 patients (110 Caucasians and 50 African-Caribbeans), 80 with an indolent tumor (ISUP group 1 + pT2), and 80 with an aggressive tumor (ISUP group more than 3 + pT3). The concentrations of 29 OCPs were measured in PPAT concomitantly with the characterization of PUFA content. Exposure patterns of OCPs differed according to the ethno-geographical origin. Most OCPs were found at higher concentration in Caucasian patients, whereas pp'-DDE content was twice as high in African-Caribbeans. Chlordecone was only detected in PPAT from African-Caribbean patients. Most OCP concentrations were positively correlated with age, and some with BMI. After adjusting for age, BMI, and PUFA composition of PPAT, no significant association was found between OCPs content and risk of aggressive disease, except of mirex which appeared inversely associated with aggressive features of PCa in Caucasian patients. These results highlight a significant ethno-geographic variation in internal exposure to OCPs, which likely reflects differences in consumption patterns. The inverse relationship observed between mirex concentration and markers of PCa aggressiveness need to be further investigated.

Differential Bioaccumulation Patterns of α, β-Hexachlorobenzene and Dicofol in Adipose Tissue from the GraMo Cohort (Southern Spain)

To identify bioaccumulation patterns of α-, β- hexachlorocyclohexane (HCH) and dicofol in relation to sociodemographic, dietary, and lifestyle factors, adipose tissue samples of 387 subjects from GraMo cohort in Southern Spain were analyzed. Potential predictors of these organochlorine pesticides (OCP) levels were collected by face-to-face interviews and assessed by multivariable linear and logistic regression. OCPs were detected in 84.2% (β-HCH), 21.7% (α-HCH), and 19.6% (dicofol) of the population. β-HCH levels were positively related to age, body mass index (BMI), mother's occupation in agriculture during pregnancy, living in Poniente and Alpujarras, white fish, milk and water consumption, and negatively related to being male, living near to an agricultural area, working ≥10 years in agriculture, and beer consumption. Detectable α-HCH levels were positively related to age, BMI, milk consumption, mother's occupation in agriculture during pregnancy, and negatively with residence in Poniente and Alpujarras, Granada city, and Granada Metropolitan Area. Residence near to an agricultural area, smoking habit, white fish and water consumption, and living in Poniente and Alpujarras, Granada city and Granada Metropolitan Area were negatively associated with detectable dicofol levels. Our study revealed different bioaccumulation patterns of α, β-HCH and dicofol, probably due to their dissimilar period of use, and emphasize the need for assessing the exposure to frequently overlooked pollutants.

Human Biomonitoring of Environmental and Occupational Exposures by GC-MS and Gas Sensor Systems: A Systematic Review

Environmental chemicals and contaminants coming from multiple external sources enter the human body, determining a potential risk for human health. Human biomonitoring (HBM), measuring the concentrations of biomarkers in human specimens, has become an emerging approach for assessing population-wide exposure to hazardous chemicals and health risk through large-scale studies in many countries. However, systematic mapping of HBM studies, including their characteristics, targeted hazardous pollutants, analytical techniques, and sample population (general population and occupationally exposed workers), has not been done so far. We conducted a systematic review of the literature related to airborne hazardous pollutants in biofluids to answer the following questions: Which main chemicals have been included in the literature, which bodily fluids have been used, and what are the main findings? Following PRISMA protocol, we summarized the publications published up to 4 February 2021 of studies based on two methods: gas-chromatography/mass spectrometry (GC/MS) and electronic noses (e-noses). We screened 2606 records and 117 publications were included in the analysis, the most based on GC/MS analysis. The selected HBM studies include measurements of biomarkers in different bodily fluids, such as blood, urine, breast milk, and human semen as well as exhaled air. The papers cover numerous airborne hazardous pollutants that we grouped in chemical classes; a lot of hazardous and noxious compounds, mainly persistent organic pollutants (POPs) and volatile organic compounds (VOCs), have been detected in biological fluids at alarming levels. The scenario that emerged from this survey demonstrates the importance of HBM in human exposure to hazardous pollutants and the need to use it as valid tool in health surveillance. This systematic review represents a starting point for researchers who focus on the world of pollutant biomonitoring in the human body and gives them important insights into how to improve the methods based on GC/MS. Moreover, it makes a first overview of the use of gas sensor array and e-noses in HBM studies.

Hokkaido birth cohort study on environment and children's health: cohort profile 2021

BACKGROUND

The Hokkaido Study on Environment and Children's Health is an ongoing study consisting of two birth cohorts of different population sizes: the Sapporo cohort and the Hokkaido cohort. Our primary objectives are to (1) examine the effects that low-level environmental chemical exposures have on birth outcomes, including birth defects and growth retardation; (2) follow the development of allergies, infectious diseases, and neurobehavioral developmental disorders, as well as perform a longitudinal observation of child development; (3) identify high-risk groups based on genetic susceptibility to environmental chemicals; and (4) identify the additive effects of various chemicals, including tobacco.

METHODS

The purpose of this report is to provide an update on the progress of the Hokkaido Study, summarize recent results, and suggest future directions. In particular, this report provides the latest details from questionnaire surveys, face-to-face examinations, and a collection of biological specimens from children and measurements of their chemical exposures.

RESULTS

The latest findings indicate different risk factors of parental characteristics on birth outcomes and the mediating effect between socioeconomic status and children that are small for the gestational age. Maternal serum folate was not associated with birth defects. Prenatal chemical exposure and smoking were associated with birth size and growth, as well as cord blood biomarkers, such as adiponectin, leptin, thyroid, and reproductive hormones. We also found significant associations between the chemical levels and neuro development, asthma, and allergies.

CONCLUSIONS

Chemical exposure to children can occur both before and after birth. Longer follow-up for children is crucial in birth cohort studies to reinforce the Developmental Origins of Health and Disease hypothesis. In contrast, considering shifts in the exposure levels due to regulation is also essential, which may also change the association to health outcomes. This study found that individual susceptibility to adverse health effects depends on the genotype. Epigenome modification of DNA methylation was also discovered, indicating the necessity of examining molecular biology perspectives. International collaborations can add a new dimension to the current knowledge and provide novel discoveries in the future.

Environmental exposure to organochlorine pesticides and its association with the risk of hearing loss in the Chinese adult population: A case-control study

Hearing loss is a common chronic sensory deficit that has become a major public health concern worldwide. Hearing loss is well documented to be induced by noise and ototoxic drugs, and the association of hearing loss with environmental pollutants has received increasing attention. Organochlorine pesticides (OCPs) are an important group of environmental pollutants that exist ubiquitously in the human body and continue to represent a significant environmental health concern. Our case-control study was performed to explore the association between serum levels of OCPs and the risk of hearing loss in China, including 87 case-control pairs. Serum concentrations of 15 OCPs were measured. Pearson's correlation analysis and principal component analysis of frequently detected (>80%) OCPs showed a different distribution pattern, indicating possible exposure sources/scenarios for the case-control adult population. A higher α-hexachlorocyclohexane (α-HCH) level was a risk factor for an increased prevalence of hearing loss. The risk of hearing loss was increased by approximately 5.25-fold in the highest tertile compared with the lowest tertile. Furthermore, a significant association of the α-HCH level with an increased hearing threshold was observed at mid/high frequencies. This study provided the first evidence indicating that exposure to α-HCH might be a potential risk factor for hearing loss.

Associations between prenatal exposure to organochlorine pesticides and thyroid hormone levels in mothers and infants: The Hokkaido study on environment and children's health

Organochlorine pesticides (OCPs) are environmental contaminants with potentially adverse effects on neurodevelopment. Previous findings on the association between prenatal exposure to OCPs and the maternal or infant thyroid hormone system are inconsistent. Moreover, the influence of exposure to multiple OCPs and other chemical compounds is not clearly understood. Our study therefore aimed to examine the association between OCP exposure and both maternal and infant thyroid hormone systems. We also explored multiple exposure effects of OCPs and the influence of each compound using weighted quantile sum (WQS) methods. The study population included 514 participants in the Hokkaido study, recruited from 2002 to 2005 at one hospital in Sapporo, Japan. To quantify 29 OCPs, maternal blood samples were analyzed using gas chromatography/mass spectrometry. Blood samples for measuring thyroid stimulating hormone (TSH) and free thyroxine (FT4) levels were obtained from mothers during the early gestational stage (mean 11.4 weeks), and from infants between 7 and 43 days of age. The data of 333 mother child pairs with OCP and thyroid hormone measurements were included in the final analyses. Multivariate regression models showed a negative association between maternal FT4 and levels of o,p'-dichlorodiphenyldichloroethylene (DDE), o,p'-dichlorodiphenyltrichloroethane (DDT), and dieldrin. The WQS analysis showed that o,p'-DDT (48.6%), cis-heptachlorepoxide (22.8%), dieldrin (15.4%) were the primary contributors to the significant multiple exposure effect of OCPs on maternal FT4. For infants, we found a positive association between FT4 and cis-nonachlor and mirex. The most contributory compounds in the multiple exposure effect were trans-nonachlor (27.1%) and cis-nonachlor (13.8%), while several compounds contributed to the WQS via small weights (0.4-9.1%). These results indicate that OCPs, even at very low levels, may influence maternal and child thyroid hormone levels, which could modulate child development.

Estimated postnatal p,p'-DDT and p,p'-DDE levels and body mass index at 42 months of age in a longitudinal study of Japanese children

BACKGROUND

Children are exposed to p,p'-dichlorodiphenyltrichloroethane (p,p'-DDT) and p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE) through placental and lactational transfer. Some studies have suggested that early-life exposure to these compounds could lead to increased body mass index (BMI) during childhood. Our aim was to assess whether children's exposure during the first 2 years of life is associated with BMI z-score in Japanese children at 42 months of age.

METHODS

We used data from a birth cohort (n = 290) of the Tohoku Study of Child Development. p,p'-DDT and p,p'-DDE levels were measured in breast milk samples collected 1 month after birth, and levels in children were estimated using a toxicokinetic model for three exposure periods (0-6 months, 6-12 months, 12-24 months). Associations between exposure estimates and BMI z-score at 42 months of age were assessed using multivariate linear regression models.

RESULTS

We found no significant association between levels of p,p'-DDT measured in breast milk or estimated in children and BMI z-score. However, we observed associations between estimated p,p'-DDE levels in girls during all postnatal exposure periods and BMI z-score; for each log increase in the estimated p,p'-DDE levels, BMI z-score increased by 0.23 (C.I. 95%: 0.01, 0.45) for the 0-6 months exposure period, 0.26 (C.I. 95%: 0.06, 0.47) for the 6-12 months exposure period, and 0.24 (C.I. 95%: 0.05, 0.43) for the 12-24 months exposure period.

CONCLUSION

In this study of Japanese children, estimated postnatal p,p'-DDE levels were associated with increased BMI z-score at 42 months of age, mostly in girls. These results are in line with previous studies supporting that early-life exposure to p,p'-DDE may be associated with higher BMI during childhood.

[Environmental Chemical Exposure and Its Effects on Infants' Reproductive Hormones]

In recent years, the birthrate has been continuously declining in Japan. The main causes of the decline are social factors. On the other hand, there is increasing evidence that many environmental chemicals show endocrine disrupting properties. Thus, we hypothesized that exposure to these chemicals would also be a causal for the fertility crisis. In this review, we examined current evidence that focused on environmental chemical exposure in utero and its association with reproductive hormones in children. We have included the findings from a prospective birth cohorts, the Hokkaido Study on Environment and Children's Health Sapporo cohort. According to the literature, environmental chemical levels in utero, such as polychlorinated biphenyl, dioxins, perfluorinated chemical substances, phthalates, and bisphenol A were somewhat associated with the levels of reproductive hormones, such as testosterone, estradiol, progesterone, inhibin B, and insulin-like factor-3 in cord blood, in early childhood and adolescence. The literature also suggests the association between exposure to these chemicals and brain-sexual differentiation or the anogenital distance, which suggests the disruption of androgen shower during the developmental stage in the fetal period. There are still knowledge gaps on whether these hormones at an early stage affect the pubertal development and reproductive functions in later life. In addition, alternative chemicals are produced after banning one type. The health effects of alternative chemicals should be evaluated. Effects of exposure to a mixture of the chemicals should also be examined in future studies. In conclusion, the prevention of environmental chemical hazards in relation to human reproductive function is important. It would be one of the countermeasures to the falling birthrate caused by fertility issues.

Dietary patterns and serum of DDT concentrations among reproductive-aged group of women in Bangladesh

This research was conducted in order to propose ways to reduce human exposure to DDT, especially for women of reproductive age in Bangladesh, and to find a relation between DDT exposure levels in serum and questionnaire information including sociodemographic and food frequency (FFQ). In this study, a significant relationship was found between the education level and BMI, and the serum p,p'-DDE concentration. This result suggests that people with higher education (relating to higher income) and BMI in Bangladesh actively buy expensive foodstuff, like meat and/or fatty fish, which relates to a higher fat intake. Additionally, a weak positive relationship between p,p'-DDE concentration in serum and the frequency of beef consumption was observed among the nullipara women subgroup. In a previous study, beef and fish showed large contributions on DDT intake of Bangladesh population. Those results suggest that the control of fatty food consumption such as meat (beef) and marine fish might help to regulate the levels of DDT.

[Importance of Two Birth Cohorts (n=20,926 and n=514): 15 Years' Experience of the Hokkaido Study on Environment and Children's Health: Malformation, Development and Allergy]

Since "Our Stolen Future" by Theo Colborn was published in 1996, global interest on the impact of chemical substances, such as the endocrine-disrupting action of chemicals, has increased. In Japan, "The Hokkaido Study on Environment and Children's Health: Malformation, Development and Allergy" was launched in 2001. It was a model of Japan Environment and Children's Study of the Ministry of the Environment. In a large-scale, Hokkaido cohort, we obtained the consent of 20,926 mothers at the organogenesis stage with the cooperation of 37 obstetrics clinics in Hokkaido. We tracked the effects of endocrine disruptors on developmental disorders. In a small-scale Sapporo cohort, we observed in detail the neuropsychiatric development of children with the consent of 514 mothers in their late pregnancy. We examined how prenatal exposure to low concentrations of environmental chemicals affect the development of organs and the postnatal development of children. Maternal exposure to POPs, such as PCB/dioxins and perfluorinated alkyl substances, has affected not only children's birth size, thyroid functions, and sex hormone levels, but also postnatal neurodevelopment, infection, and allergy among others. The associations of short-half-life substances, such as DEHP and BPA, with obesity, ASD, and ADHD have been investigated. Gene-environment interactions have been found for smoking, caffeine, folic acid, and PCB/dioxin. In 2015, our center was officially designated as the WHO Collaborating Centre for Environmental Health and Prevention of Chemical Hazards, and we continue to the contribute to the global perspectives of child health.

Socio-demographic and behavioural determinants of body mass index among an adult population in rural Northern Ghana: the AWI-Gen study

BACKGROUND

Obesity and associated cardiometabolic diseases are increasing in urban sub-Saharan Africa due to a complex epidemiological and nutritional transition. Related data on rural communities is scarce.

OBJECTIVES

The study characterized the socio-demographic and behavioural factors influencing body mass index (BMI) among adults in rural Northern Ghana Methods: A population-based cross-sectional study involving adults aged 40-60 years residing in the Kassena-Nankana districts was undertaken. Demographic, socio-economic and behavioural data were collected along with measures of anthropometry. We determined factors associated with BMI among women and men.

RESULTS

A total of 2014 adults were studied. The median age was 51 (IQR 45-57) years and 54% were women. The prevalence of overweight/obesity was higher among women than men (18.4% vs. 7.2%; p < 0.001), whilst underweight was more prevalent in men (18.3% vs. 13.1%; p = 0.001). Participants with the highest level of education and a high household socio-economic status had higher BMIs than those in the lowest strata in both men (β = 0.074, p = 0.028 and β = 0.072, p < 0.001, respectively) and women (β = 0.174, p = 0.001 and β = 0.109, p < 0.001, respectively). Men (β = -0.050; p < 0.001) and women (β = -0.073; p < 0.001) of the Nankana ethnic group had a lower BMI than the Kassena ethnic group. Among men, alcohol consumption (β = -0.021; p = 0.001) and smoking (β = -0.216; p < 0.001) were associated with lower BMI. Smokeless tobacco was associated with lower BMI among women. Pesticide exposure was associated with higher BMI (β = 0.022; p = 0.022) among men.

CONCLUSION

Age, sex, ethno-linguistic group and prevailing socio-demographic and behavioural factors within this rural community in Northern Ghana influence BMI. The observed positive association between pesticide use and BMI warrants further investigation.

Prenatal organochlorine pesticide exposure and the disruption of steroids and reproductive hormones in cord blood: The Hokkaido study

Certain organochlorine pesticides (OCPs) are designated as persistent organic pollutants and are regulated in many countries. The effects of OCPs on pediatric endocrinology are a concern; however, only limited data exist from human studies on maternal OCP exposure and its effects on infants' hormone levels. This study was conducted as part of the Hokkaido Study Sapporo Cohort, a prospective birth cohort study in Japan. Participants included 514 women who enrolled at 23-35weeks of gestation between 2002 and 2005; maternal blood samples were collected in late pregnancy, and 29 OCPs were measured. Reproductive and steroid hormone levels in cord blood were also determined. Characteristics of mothers and their infants were obtained from self-administered questionnaires and medical records. Ultimately, 232 samples with both OCP and hormone data were analyzed. Fifteen of 29 investigated OCPs were detected in over 80% of the samples, with p,p'-dichlorodiphenyldichloroethylene showing the highest concentration (median value: 619pg/g-wet). The association between OCPs and sex hormone levels varied by sex. Linear regression models after sex stratification showed that chlordanes, cis-hexachlorobenzene, heptachlor epoxide, Mirex, and toxaphenes in maternal blood were inversely associated with testosterone, cortisol, cortisone, sex hormone-binding globin, prolactin, and androstenedione-dehydroepiandrosterone (DHEA) and testosterone-androstenediones ratios among boys. Furthermore, these OCPs were positively correlated with DHEA, follicle stimulating hormone (FSH), and adrenal androgen-glucocorticoid and FSH-inhibin B ratios among boys. In categorical quartile models, testosterone and DHEA were inversely and positively associated with OCPs, respectively. Estradiol-testosterone and adrenal androgen-glucocorticoid ratios tended to increase with increasing OCP concentrations in the higher quartile, while the testosterone-androstenedione ratio tended to decrease. Sex hormone-binding globulin and prolactin showed an inverse association with OCPs. Among girls, the linear regression model showed that only p,p'-dichlorodiphenyltrichloroethane was inversely associated with the level of DHEA and the adrenal androgen-glucocorticoid ratio, but was positively associated with cortisone levels. However, no associations were observed using the quartile categorical model. These results suggest that prenatal exposure to OCPs disrupt reproductive hormones of fetuses in utero among boys, even at relatively low levels.

Toxicological profile of organochlorines aldrin and dieldrin: an Indian perspective

Several epidemiological studies have suggested various environmental factors as a possible cause for increased incidence of various abnormalities. Of the various environmental contaminants, the most prevalent and the most discussed are the endocrine disrupting chemicals. Contact of such disruptors with humans has become inevitable today. They are cosmopolitan and present from agriculture to industrial sectors, even in day-to-day consumer products. Aldrin and dieldrin belong to one such class of substances which are known to have a toxic effect on various physiological systems of the human body. Despite an imposed ban on their manufacture and commercial use, these pesticides could still be detected in probable areas of consumption like agriculture. The present review discusses the known possible toxic effects of aldrin and dieldrin and their current existence in the ecosystem across India.

Association between prenatal exposure to organochlorine pesticides and the mental and psychomotor development of infants at ages 6 and 18 months: The Hokkaido Study on Environment and Children's Health

Organochlorine pesticides (OCPs) are environmental contaminants that persist in the environment and bioaccumulate through the food chain in humans and animals. Although previous studies have shown an association between prenatal OCP exposure and subsequent neurodevelopment, the levels of OCPs included in these studies were inconsistent. A hospital-based prospective birth cohort study was conducted to examine the associations between prenatal exposure to relatively low levels of OCPs and neurodevelopment in infants at 6 (n=164) and 18 (n=115)months of age. Blood samples were analyzed using gas chromatography/mass spectrometry techniques to quantify 29 OCPs. The Bayley Scales of Infant Development 2nd edition (BSID-II) was used to assess the Mental and Psychomotor Developmental Index. After controlling for confounders, we found an inverse association between prenatal exposure to cis-heptachlor epoxide and the Mental Developmental Index at 18 months of age. Furthermore, infants born to mothers with prenatal concentrations of cis-heptachlor epoxide in the highest quartile had Mental Developmental Index scores -9.8 (95% confidence interval: -16.4, -3.1) lower than that recorded for infants born to mothers with concentrations of cis-heptachlor epoxide in the first quartile (p for trend <0.01). These results support the hypothesis that prenatal exposure to OCPs, especially cis-heptachlor epoxide, may have an adverse effect on the neurodevelopment of infants at specific ages, even at low levels.

Pesticide exposure in the local community of Vehari District in Pakistan: An assessment of knowledge and residues in human blood

The present study is based on cross-sectional data collected from rural and market areas of Vehari District in Pakistan to assess public awareness of pesticide risks and determine the levels of exposure to organochlorine pesticides (OCPs) in the local community. Blood samples were collected from 56 volunteer donors (VDs) including children, female workers, farm workers involved in pesticide business, farm workers involved in pesticide spraying activities, and people who were living away from agricultural fields. Blood analysis showed that VDs who were involved in spraying activities had significantly higher levels of OCP residues in their blood samples than VDs from the other groups, with mean concentrations of 1.13, 0.92, 0.68 and 1.96ngmL^-1 for pp-DDT, aldrin, dieldrin, and endosulfan, respectively. However, VDs who were living away from agricultural fields had significantly lower levels of pesticide residues in their blood samples, with mean concentrations of 0.30, 0.19, 0.14 and 0.41ngmL^-1 for pp-DDT, aldrin, dieldrin, and endosulfan, respectively. A survey of 179 volunteer respondents (VRs) showed that a significant proportion of the VRs had little knowledge of using the recommended amounts of pesticides (65.9%). Furthermore, the majority of the VRs was found using limited protective measures during pesticide use (62.6%) and was practising unsafe storage of pesticides (87.7%). In addition, most farm workers (88.8%) reported an increasing trend in pesticide use in their farms each year. Knowledge of pesticide risks on human health increased with formal education and training. Poor knowledge regarding pesticide risks and handling among inhabitants of Vehari District contribute to high exposure levels to OCPs, particularly among farm workers. Findings are useful for policy formulation aimed at reduction of pesticide exposure in Pakistan.

The Hokkaido Birth Cohort Study on Environment and Children's Health: cohort profile-updated 2017

The Hokkaido Study on Environment and Children's Health is an ongoing study consisting of two birth cohorts of different population sizes: the Sapporo cohort and the Hokkaido cohort. Our primary study goals are (1) to examine the effects of low-level environmental chemical exposures on birth outcomes, including birth defects and growth retardation; (2) to follow the development of allergies, infectious diseases, and neurobehavioral developmental disorders and perform a longitudinal observation of child development; (3) to identify high-risk groups based on genetic susceptibility to environmental chemicals; and (4) to identify the additive effects of various chemicals, including tobacco smoking. The purpose of this report is to update the progress of the Hokkaido Study, to summarize the recent results, and to suggest future directions. In particular, this report provides the basic characteristics of the cohort populations, discusses the population remaining in the cohorts and those who were lost to follow-up at birth, and introduces the newly added follow-up studies and case-cohort study design. In the Sapporo cohort of 514 enrolled pregnant women, various specimens, including maternal and cord blood, maternal hair, and breast milk, were collected for the assessment of exposures to dioxins, polychlorinated biphenyls, organochlorine pesticides, perfluoroalkyl substances, phthalates, bisphenol A, and methylmercury. As follow-ups, face-to-face neurobehavioral developmental tests were conducted at several different ages. In the Hokkaido cohort of 20,926 enrolled pregnant women, the prevalence of complicated pregnancies and birth outcomes, such as miscarriage, stillbirth, low birth weight, preterm birth, and small for gestational age were examined. The levels of exposure to environmental chemicals were relatively low in these study populations compared to those reported previously. We also studied environmental chemical exposure in association with health outcomes, including birth size, neonatal hormone levels, neurobehavioral development, asthma, allergies, and infectious diseases. In addition, genetic and epigenetic analyses were conducted. The results of this study demonstrate the effects of environmental chemical exposures on genetically susceptible populations and on DNA methylation. Further study and continuous follow-up are necessary to elucidate the combined effects of chemical exposure on health outcomes.

Application of the QuEChERS method for the determination of organochlorine pesticide residues in Brazilian fruit pulps by GC-ECD

The Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) method was applied to the extraction of 14 organochlorine pesticides (OCPs) residues from commercial fruit pulps available in supermarkets in Fortaleza, Northeastern Brazil. The analyses were carried out by gas chromatography (GC), coupled to an electron-capture detector (ECD), and were confirmed by GC-tandem mass spectrometry (MS). The parameters of the analytical method, such as accuracy, precision, linear range, limits of detection and quantification, were determined for each pesticide. The results showed good linearity (R² ≥ 0.9916) and the overall average recoveries were considered satisfactory obtaining values between 69 and 110%, RSD of 2-15 %, except for hexachlorobenzene (HCB) in açai, acerola and guava pulp samples. The OCPs were detected in guava (α-HCH; lindane) and soursop (α, β-HCH isomers) samples. The QuEChERS method and GC-ECD were successfully used to analyze OCPs in commercially available Brazilian fruit pulps and can be applied in routine analytical laboratories.

Pesticide Exposures and Body Mass Index (BMI) of Pesticide Applicators From the Agricultural Health Study

Endocrine-disrupting chemicals, including pesticides, may be associated with weight gain. This is the first longitudinal study to examine a potential association between weight gain and pesticides using data on 8,365 male pesticide applicators from the Agricultural Health Study (AHS) cohort established in 1993. The relationship between total cumulative days of exposure to pesticide functional/chemical classes and to the four most frequently used individual pesticides was studied in relation to body mass index (BMI) at the time of 5-yr follow-up (beginning in 1998) with the length of the exposure period dating back to age 20 yr. Multiple regression, Spearman correlation, ordinal logistic regression, and logistic regression models all utilized a Bonferroni-adjusted p value, were adjusted for relevant covariates, and were stratified by state of residence (Iowa/North Carolina) and presence/absence of weight-related health conditions. Adjusted multiple regression yielded statistically significant positive parameter estimates for the study sample and Iowa subgroups with consistent findings for triazine herbicides and atrazine: Change in BMI per 100 cumulative pesticide exposure days ranged from 0.07 to 0.11 for triazine herbicides and from 0.10 to 0.19 for atrazine. Ordinal logistic regression compared normal weight with overweight and with obese using the zero exposure category as referent. Statistically significant adjusted odds ratios identified for the study sample and both state subgroups for the highest level of atrazine exposure ranged from 1.4 to 1.7. Further investigation is warranted to evaluate the associations identified here.

Prenatal stress and development: beyond the single cause and effect paradigm

Our awareness of the causes of stress-induced developmental dysfunction has increased dramatically over the past decade, and it is becoming increasingly clear that a number of factors can have considerable impacts on the developing fetus. Although there is a tendency in investigations of developmental teratogens to attribute specific causes to adverse fetal outcomes, it is important we recognize that for most developmental dysfunctions it is unlikely a single cause, but yet a series of environmental insults combined with genetic predisposition that ultimately leads to a disease state. Nonetheless, a number of developmental teratogens, such as maternal psychological stress and chemical exposures, have been shown to increase the likelihood of developmental defects. These defects can manifest during development, leading to observable birth defects, or could become evident long after birth, even into adulthood. In addition, epigenetic mutations in the germline can alter the phenotype of successive generations through transgenerational inheritance, and in this way environmental factors can alter the developmental outcomes and disease predispositions of future generations. Understanding this complexity is essential to interpretations of causality in the studies of stress-induced developmental dysfunction and needs to be fully considered to more effectively interpret potential outcomes.

Ten years of progress in the Hokkaido birth cohort study on environment and children's health: cohort profile--updated 2013

The Hokkaido Study on Environment and Children's Health is an ongoing cohort study that began in 2002. The study consists of two prospective birth cohorts, the Sapporo cohort (n = 514) and the Hokkaido large-scale cohort (n = 20,940). The primary goals of this study are to first examine the potential negative effects of perinatal environmental chemical exposures on birth outcomes, including congenital malformations and growth retardation; second, to evaluate the development of allergies, infectious diseases and neurodevelopmental disorders and perform longitudinal observations of the children's physical development to clarify the causal relationship between these outcomes and environmental chemicals; third, to identify individuals genetically susceptible to environmental chemicals; finally, to identify the additive effects of various environmental factors in our daily life, such as secondhand smoke exposure or low folate intake during early pregnancy. In this paper, we introduce our recent progress in the Hokkaido study with a cohort profile updated in 2013. For the last ten years, we followed pregnant women and their offspring, measuring various environmental chemicals, i.e., PCB, OH-PCB and dioxins, PFCs (Perfluorinated Compounds), Organochlorine pesticides, Phthalates, bisphenol A and mercury. We discovered that the concentration of toxic equivalents (TEQ) of dioxin and other specific congeners of PCDF or PCDD have effects on birth weight, infants' neurodevelopment and immune function. There were significant gender differences in these effects; our results suggest that male infants have more susceptibility to those chemical exposures than female infants. Interestingly, we found maternal genetic polymorphisms in AHR, CYP1A1 or GSTs that significantly modified the dioxin concentrations in maternal blood, suggesting different dioxin accumulations in the bodies of individuals with these genotypes, which would lead to different dioxin exposure levels. These genetic susceptibility factors influenced the body size of children born from mothers that either smoked or were passively exposed to tobacco smoke. Further studies investigating the correlation between epigenetics, the effects of intrauterine exposure to environmental chemicals and developmental factors related to health and disease are warranted.

A method developed for determination of heptachlor and its metabolites from pork

A new method has been developed to determine heptachlor and its metabolites heptachlor-exo-epoxide and heptachlor-endo-epoxide in pork. The pork samples were extracted with acetone-n-hexane (2:8, V:V) and cleaned up by gel permeation chromatography and florisil solid-phase extraction cartridge. The extract was then determined by gas chromatography equipped with electron capture detector (GC-ECD), followed by validation using gas chromatography-mass spectrometry (GC-MS) with negative chemical ionization. Linearity of calibration curves ranged from 0.01 to 0.5 mg L(-1), with correlation coefficients of more than 0.9980 for GC-ECD and GC-MS, respectively. At spiked concentrations of 0.01, 0.05, and 0.1 mg kg(-1), the average recovery and relative standard deviation values were 87.1-102.2 and 4.0-11.3%, respectively. The limit of quantification for each analyte was 0.01 mg kg(-1), which satisfied the current maximum residue limit permitted in pork. Our results showed that the method developed was successfully used to determine heptachlor and heptachlor epoxide residues in real pork samples.

Concentrations of organochlorine pesticides (OCPs) in human blood plasma from Hong Kong: markers of exposure and sources from fish

Previous studies revealed that food, particularly fish products, is the major source for human exposure to organochlorine pesticides (OCPs). Our previous studies revealed that contamination of Hong Kong market fish with DDT was 0.74-131 with a mean of 12.2 ng g(-1), ww, a result suggested that local people might be exposed to hazardous concentrations of OCPs. Therefore, the present systematic study was conducted to determine concentrations of OCPs in blood plasma of Hong Kong residents, develop marker substances and evaluate sources of 19 individual OCPs from fish. Concentrations of ∑OCPs, ∑DDTs and ∑HCHs ranged from 294 to 9732, 172 to 8842, and 115 to 1616 ng g(-1) lipid weight (lw), respectively. These concentrations were greater than those in blood of people from most developed countries but lower than those from most developing countries. The upper age group (>50 years) had significant (p<0.05) greater concentrations of OCPs than other groups. Furthermore, concentrations of OCPs in males were significantly (p<0.05) greater than those in females. p, p'-DDE was the predominant congener and marker substance of DDTs, while β-HCH was the predominant congener and marker substance of HCHs. p, p'-DDE was more correlated with ∑OCPs (r(2)=0.830, p<0.05) than other individual OCPs, which suggested that p, p'-DDE is a good marker for accumulation of OCPs in blood plasma. Concentrations of individual OCPs were significantly correlated with not only their corresponding total concentrations in fishes from Hong Kong markets (r(2)=0.391, p=0.024), but also their bioaccessible fractions, which were estimated by an in vitro digestion method (r(2)=0.784, p=0.000). These results suggested that the in vitro gastrointestinal model is a more accurate method to evaluate accumulation of and health risks caused by dietary intake of OCPs. This study, which was the first systematic study to investigate concentrations of OCPs in blood of Hong Kong people, provides a baseline to which future measurements can be compared.