Organochlorine pesticide levels in maternal serum and risk of neural tube defects in offspring in Shanxi Province, China: a case-control study

Exposure to pesticides during pregnancy and the risk of neural tube defects: A systematic review

Exposure to pesticides during pregnancy has been associated with several serious congenital malformations, such as neural tube defects, therefore, is a cause for concern in terms of human health. This review aims to gather information related to maternal exposure during pregnancy and the risk of triggering neural tube defects in the offspring. The search strategy for the studies followed the PRISMA guidelines. We conducted a systematic search in the Science Direct, PubMed, Cochrane Library, Embase, Scopus, and Web of Science databases for all epidemiological studies that sought to associate exposure to pesticides during embryonic development with the risk of neural tube defects (NTDs). The keywords used were "pesticide", "herbicide", "congenital" and "neural". Of the 229 articles, 8 eligible ones (7 case-control and 1 cross-sectional) evaluated pesticide exposure in pregnancy. Different methods were used, including analysis of biological samples and questionnaires. The pesticides studied included insecticides, herbicides, fungicides, and nematicides. Insecticides were the most studied, with variations in concentrations between tissues and studies. Distinct levels of pesticides have been detected in maternal serum, placenta, and umbilical cord. Models were statistically adjusted for confounding factors, such as smoking and dietary supplement intakes. Concentrations were measured in different exposure windows (periconception and prenatal), related to NTDs such as anencephaly and spina bifida. Different data collection techniques, types of biological samples, and exposure windows were used, which made comparison difficult. The main pesticides studied included DDT, DDE, HCH, and endosulfan. Maternal serum showed the highest concentrations of pesticides, but detection in placental tissue and umbilical cord confirms embryonic exposure. Confounding variables were adjusted for in the analysis of the articles, but they may still contribute to the risk of NTDs. All the studies analyzed pesticide exposure and the relationship with NTDs. However, a more standardized survey would be ideal for better comparisons.

The toxicokinetics and risk assessment of pyrethroids pesticide in tilapia (Oreochromis mossambicus) upon short-term water exposure

Pyrethroids pesticides (PPs) are the widely adopted synthetic pesticides for agriculture and fishery. The frequent use of these pesticides leads to the accumulation of residues in the freshwater environments in China, subsequently affecting aquatic organisms and ecosystems. However, there are few reports on the toxicological and risk assessment of aquaculture aquatic products. In this study, the uptake, depuration kinetics and potential risk to human health and ecology of fenpropathrin, cypermethrin, fenvalerate, and deltamethrin were assessed using tilapia. The results indicated that four PPs were readily accumulated by tilapia. The bioconcentration factors (BCF) of the PPs in plasma and muscle were between 71.3 and 2112.1 L/kg and 23.9-295.3 L/kg, respectively. The half-lives (t_1/2) of muscle and plasma were 2.90-9.20 d and 2.57-8.15 d. The risks of PPs residues in the muscle of tilapia and exposed water were evaluated by hazard quotient (HQ) and risk quotient (RQ). Although PPs residues in tilapia had a low dietary risk to human health, the residues in the exposed water had a high ecological risk to fish, daphnia, and green algae. Therefore, assessing the PPs content in freshwater aquaculture and monitoring their dosages and frequencies are highly necessitated to avoid their adverse effect on the aquaculture environment.

High spatial resolved cropland coverage and cultivation category determine neonicotinoid distribution in agricultural soil at the provincial scale

Croplands are experiencing increasing neonicotinoid pollution and ecological health problems, which are especially widely applied in China. However, the large regional scale distribution of neonicotinoids and the key factors have seldom been determined. We show that the total residual concentration of neonicotinoids ranged from 13.4 to 157 ng/g with an average level of 75.8 ng/g and imidacloprid which was the dominant compound ranged from 10.4 to 81.3 ng/g during 2017-2021 in the Yangtze River Delta, China. In comparison, the neonicotinoid residues detected here were mostly higher than those in other regions. We further show that the 1-km spatial resolution cropland coverage (78.0%) and crop type (18.1%) predominantly contributed to the large spatial variation of neonicotinoids after adjusting for the factors including temperature, soil pH, soil moisture, and precipitation via automatic linear regression modeling at the provincial scale. Additional analyses revealed that tea croplands had significantly lowest concentration and fruit fields had the highest level due to the different application methods. Our findings provide new insight into key factors quantifying the high spatial resolved distribution of neonicotinoids and urgently call for reasonable application methods against rapidly growing ecology threats from neonicotinoid pollution in China.

Distribution and partitioning of pyrethroid insecticides in agricultural lands: Critical influencing factors

Pyrethroid insecticides are widely applied due to the broad spectrum and high efficiency in pest control and detected in various environmental media, but the key factor affecting their occurrence and distribution in agricultural lands is still not clear. Here, we measured pyrethroid residues in 644 surface soil and 630 surface water samples and quantified the impacts of various factors on the distribution and partition of pyrethroids through a large-scale field study in Southeast China during 2015-2017. The pyrethroid residues were widely detected in the studied areas, and the mean concentration of seven individual pyrethroids in surface soil and water ranged from 0.10 (cyfluthrin, (CYF)) to 12.14 ng/g (bifenthrin, (BIF)) and 0.18 (CYF) to 3.36 µg/L (BIF) respectively, which were higher than other regions in China and some other countries. Using a generalized linear model coupled with dominance analysis, we found that the crop type and season were significantly associated with pyrethroid residues in surface soil and water (p < 0.05). The crop difference dominated the variances of the distribution of pyrethroid residues in the surface soil and water with a contribution of more than 55% and followed by the factor of season difference. The findings provide new insight into the distribution and partitioning of pyrethroids in agricultural lands and insecticide control on ecological safety and public health.

Bioaccessibility dependence of dietary exposure to dichlorodiphenyltrichloroethane and its metabolites and hexachlorocyclohexane isomers and their induced health risk: A case study in Beijing City, China

Bioaccessibility is essential for evaluating dietary intake of contaminants. However, there is insufficient information on the dependence of dietary intake and risk assessment of dichlorodiphenyltrichloroethane and its metabolites (DDXs) and hexachlorocyclohexane isomers (HCHs) on bioaccessibility. Here, we investigated the bioaccessibilities of DDXs and HCHs in various foods and their influences on assessing exposure in the residents of Beijing City, China. Forty-three major foods in five types (fruit, vegetables, cereals, aquatic food, and meat) were sampled, and the bioaccessibility of DDXs and HCHs was evaluated using a static in vitro gastrointestinal digestion model. The bioaccessibility of DDXs in different food types ranked in the order of meat > vegetables > fruit > cereals > aquatic food, with mean ± standard deviation values of 62.2 ± 22.1%, 20.5 ± 10.6%, 12.4 ± 3.66%, 11.2 ± 9.69%, and 10.7 ± 4.97%, respectively. The highest average bioaccessibility of HCHs was found in meat (83.4 ± 14.2%), followed by fruit (41.0 ± 12.5%), vegetables (37.6 ± 18.1%), aquatic foods (24.2 ± 9.22%), and cereals (8.73 ± 4.07%). The estimated daily intakes (EDI) of the sum of DDXs and the sum of HCHs based on the bioaccessible concentration were only about 17% and 55% of the total EDI based on the residual concentration, respectively. Meat was found to play a more important role in EDI after bioaccessibility correction. The proportion of the population with potential non-carcinogenic and carcinogenic risks markedly decreased when considering bioaccessibility. It was concluded that bioaccessibility should be integrated into dietary exposure evaluation.

Prenatal exposure to organochlorine pesticides is associated with increased risk for neural tube defects

Neural tube defects (NTDs) are among the most common and disabling fetal congenital defects. Organochlorine pesticides (OCPs) are ubiquitous in the environment. In this study, 119 women who had NTD-affected pregnancies (cases) and 119 women who delivered healthy neonates (controls) were recruited in a rural area of Northern China. We used concentrations of OCPs in umbilical cord tissue as markers of prenatal exposure to investigate the association between in utero exposure to OCPs and NTD risk. Concentrations of 20 OCPs were quantified by gas chromatography-mass spectrometry, and 16 of the 20 OCPs were included in the analyses. Odds ratios and 95% confidence intervals (95% CIs) for the associations between levels of individual OCPs and NTD risk were estimated separately with logistic regression adjusting for potential confounders. The combined effects of exposure to the 16 OCPs as a mixture were analyzed with Bayesian kernel machine regression (BKMR). Logistic regression showed that the risk for NTDs increased 5.44-fold (95% CI, 2.21-13.41) for β-hexachlorocyclohexane, 2.51-fold (95% CI, 1.07-5.86) for endosulfan I, 3.78-fold (95% CI, 1.60-8.89) for endosulfan II, 3.42-fold (95% CI, 1.44-8.12) for ο,ρ'-dichlorodiphenyldichloroethane, and 2.89-fold (95% CI, 1.22-6.86) for ρ,ρ'-dichlorodiphenyltrichloroethane when the concentration of each of these OCPs was above its median (exposed) compared to below its median (non-exposed). Other OCPs were not associated with NTD risk in multivariate models. In BKMR, NTD risk increased almost linearly with concentrations of the 16 OCPs as a mixture, which suggests joint effects on NTD risk. Exposure to α-hexachlorocyclohexane, β-hexachlorocyclohexane, endosulfan II, ο,ρ'-dichlorodiphenyldichloroethane, and ρ,ρ'-dichlorodiphenyldichloroethane was associated with an increased risk for NTDs when levels of the remaining 15 OCPs were taken into account. Taken together, these findings show that prenatal exposure to OCPs is associated with increased risk for NTDs.

Distribution and sources of DDT and its metabolites in porewater and sediment from a typical tropical bay in the South China Sea

Dichlorodiphenyltrichloroethane (DDT) is well known for its harmful effects and has been banned around the world. However, DDT is still frequently detected in natural environments, particularly in aquaculture and harbor sediments. In this study, 15 surface sediment samples were collected from a typical tropical bay (Zhanjiang Bay) in the South China Sea, and the levels of DDT and its metabolites in sediment and porewater samples were investigated. The results showed that concentrations of DDXs (i.e., DDT and its metabolites) in bulk sediments were 1.58-51.0 ng g^-1 (mean, 11.5 ng g^-1). DDTs (DDT and its primary metabolites, dichlorodiphenyldichloroethane (DDD) and dichlorodiphenyldichloroethylene (DDE)) were the most prominent, accounting for 73.2%-98.3% (86.1% ± 12.8%) of the DDXs. Additionally, high-order metabolites (i.e., 1-chloro-2,2-bis(4'-chlorophenyl)ethylene (p,p'-DDMU), 2,2-bis(p-chlorophenyl)ethylene (p,p'-DDNU), 2,2-bis(p-chlorophenyl)ethanol (p,p'-DDOH), 2,2-bis(p-chlorophenyl)methane (p,p'-DDM), and 4,4'-dichlorobenzophenone (p,p'-DBP)) were also detected in most of the sediment and porewater samples, with DDMU and DBP being predominant. The DDTs concentration differed among the sampling sites, with relatively high DDTs concentrations in the samples from the aquaculture zone and an area near the shipping channel and the Haibin shipyard. The DDD/DDE ratios indicated a reductive dichlorination of DDT to DDD under anaerobic conditions at most of the sampling sites of Zhanjiang Bay. The possible DDT degradation pathway in the surface sediments of Zhanjiang Bay was p,p'-DDT/p,p'-DDD(p,p'-DDE)/p,p'-DDMU/p,p'-DDNU/ … /p,p'-DBP. The DDXs in the sediments of Zhanjiang Bay were mainly introduced via mixed sources of industrial DDT and dicofol, including fresh input and historical residue. The concentrations of DDXs in porewater samples varied from 66.3 to 250 ng L^-1, exhibiting a distribution similar to that in the accompanying sediments. However, the content of high-order metabolites was relatively lower in porewater than in sediment, indicating that high-order degradation mainly occurs in particles. Overall, this study helps in understanding the distribution, source, and degradation of DDT in a typical tropical bay.

Concentrations of organochlorine pesticides in placental tissue are not associated with risk for fetal orofacial clefts

Previous epidemiological studies have shown that prenatal exposure to organochlorine pesticides (OCPs) entails a variety of adverse impacts on fetal health, but it is not yet known whether it is associated with risk for orofacial clefts (OFCs). This study of 103 fetuses or newborns with a diagnosis of OFCs (cases) and 103 healthy newborns without malformations (controls) examined whether prenatal exposure to OCPs, as indicated by their concentrations in placental tissue, is a risk factor for OFCs. No differences were found in the median concentrations of OCPs between cases and controls, with exception of o,p'-dichlorodiphenyldichloroethylene, o,p'-dichlorodiphenyldichloroethane, and total o,p'-dichlorodiphenyltrichloroethane (DDTs), whose concentrations were higher in controls than in cases (Ps < 0.05). Although higher concentrations of placental δhexachlorocyclohexane and isodrin were found to be associated with decreased risk for OFCs in logistic regression, no association was observed in the Bayesian kernel machine regression, a novel statistical model in analyzing exposure mixtures. Women who reported periconceptional folic acid supplementation had lower placental concentrations of DDTs than women who did not. In conclusion, no association between levels of OCPs in placental tissue and risk for OFCs was observed in this population. Supplementation with folic acid may help decrease the levels of DDTs in placental tissue, but further studies are needed to confirm this unexpected finding.

Estrogens in municipal wastewater and receiving waters in the Beijing-Tianjin-Hebei region, China: Occurrence and risk assessment of mixtures

The potentially high release of estrogens to surface waters due to high population density and local livestock production in the Beijing-Tianjin-Hebei region may pose adverse effects on reproductive systems of aquatic organisms. This study found that total measured concentrations of estrone (E1), 17β-estradiol (E2), estriol (E3), 17α-ethinylestradiol (EE2) and diethylstilbestrol (DES) were 468 ± 27 ng/L in treated wastewater and 219 ± 23 ng/L in river waters in this region. E2, E3 and EE2 were the predominant estrogens in river waters. The restriction of DES for human use should have been enforced, however concentrations of DES were relatively high compared to other studies. Haihe and Yongdingxin Rivers delivered approximately 1.8 tonnes of estrogens to the Bohai Bay annually. Concentrations of individual estrogens were significantly higher in river waters in the dry season, however, mass loadings were significantly higher in the wet season. The average E2-equivalent concentrations reached 1.2 ± 0.2 and 0.64 ± 0.08 μg-E2/L following long-term and short-term exposure estimates, respectively, in river waters with an EE2 contribution of over 90 %. This could give rise to high risks to fish. Estrogens in river waters largely derived from human excretion. Field studies on estrogenic effects on fish reproductive systems are required locally considering high estrogen contamination levels.

Review of the Effects of Perinatal Exposure to Endocrine-Disrupting Chemicals in Animals and Humans

Maternal exposure to endocrine-disrupting chemicals (EDCs) is associated with long-term hormone-dependent effects that are sometimes not revealed until maturity, middle age, or adulthood. The aim of this study was to conduct descriptive reviews on animal experimental and human epidemiological evidence of the adverse health effects of in utero and lactational exposure to selected EDCs on the first generation and subsequent generation of the exposed offspring. PubMed, Web of Science, and Toxline databases were searched for relevant human and experimental animal studies on 29 October 29 2018. Search results were screened for relevance, and studies that met the inclusion criteria were evaluated and qualitative data extracted for analysis. The search yielded 73 relevant human and 113 animal studies. Results from studies show that in utero and lactational exposure to EDCs is associated with impairment of reproductive, immunologic, metabolic, neurobehavioral, and growth physiology of the exposed offspring up to the fourth generation without additional exposure. Little convergence is seen between animal experiments and human studies in terms of the reported adverse health effects which might be associated with methodologic challenges across the studies. Based on the available animal and human evidence, in utero and lactational exposure to EDCs is detrimental to the offspring. However, more human studies are necessary to clarify the toxicological and pathophysiological mechanisms underlying these effects.

An efficient method to simultaneously analyze multi-class organic pollutants in human serum

The degree of population exposure to various organic pollutants (OPs), including polycyclic aromatic hydrocarbons, organochlorinated pesticides, polychlorinated biphenyls, and polybrominated diphenyl ethers, can be determined by measuring their concentrations in human serum. However, performing large-scale measurements with such a variety of compounds in serum is challenging in terms of efficiency and cost. We describe herein the development of a high-efficiency extraction and sample cleanup protocol for simultaneous and quantitative analyses of OPs using gas chromatography-mass spectrometry. OPs, together with crude lipid impurities, were extracted from human serum with a mixture of n-hexane and methyl tert-butyl ether. A disperse sorbent composed of primary secondary amine and C18 (PSA/C18) was used to roughly remove co-extracted impurities. A combined column of neutral silica gel and neutral alumina oxide (AlO/SiG) was then used for deep cleanup. For the removal of impurities, the overall performance of our protocol for the analysis of OPs in serum was comparable to that of traditional gel permeation chromatography (GPC) and dramatically better than that of PSA/C18, which is a frequently used QuEChERS (quick, easy, cheap, effective, rugged, safe) based method. While both the proposed protocol and GPC yielded recoveries of 80%-110% for four classes of OPs, our protocol consumed about 10 times less solvent, resulting in lower experimental expenses and a lower risk of contamination from residual OPs in the solvent and other supplies. In contrast to GPC, our protocol also permits efficient batch processing of serum samples, allowing for large sample sizes such as those encountered in epidemiological studies.

Ecological risk assessment of the increasing use of the neonicotinoid insecticides along the east coast of China

In the past two decades, neonicotinoid insecticides have been widely used in agricultural activities in China. Many previous studies have investigated the neonicotinoid pollution in aquatic ecosystems, but the status of water safety of neonicotinoid uses in China is very scarce. The present study aims to reveal the spatial and temporal distribution of neonicotinoids in rivers, and then evaluate the ecological risks to aquatic animals. Water samples were collected from all sixteen rivers along the east coast of China during the dry and wet seasons in 2016, and nine individual commercialized neonicotinoids were quantified. Higher concentrations were found during the dry season (343 ± 210 ng/L) compared to those during the wet season (174 ± 162 ng/L). The concentration of neonicotinoid insecticides in river water is mainly affected by the intensity of agricultural activities. The spatial and temporal pollution patterns we discovered suggested the use of neonicotinoids has shifted from old types (i.e., imidacloprid and acetamiprid) to new types (i.e., dinotefuran and nitenpyram) in some areas. The estimated annual quantity of neonicotinoids released into the adjacent seas totaled 1256 ± 780 tons, most of which (95%) ran into the East China Sea due to heavy agricultural use in the Yangtze River Basin. Using the species sensitive distribution (SSD) method, the thresholds for aquatic animals were determined (acute: 362 ng/L; chronic: 58 ng/L). Under current agricultural practices, 27% and 84% of the river water samples exceeded the thresholds for acute and chronic ecological risks, suggesting intervention programs are in urgent need to ensure river water safety for aquatic life in China.

Association of maternal chronic arsenic exposure with the risk of neural tube defects in Northern China

Numerous animal studies have shown that high arsenic exposure can induce neural tube defect (NTD) formation. However, epidemiological evidence related to this finding is scarce. The key objective of our study is to evaluate whether maternal arsenic exposure is associated with NTD risk in Northern China. Our case-control study was conducted in 11 countries or cities in Shanxi and Hebei provinces during 2003-2007. A total of 774 mothers were included as participants: 511 controls and 263 cases (including 123 with anencephaly, 115 with spina bifida, 18 with encephalocele, and 7 with other NTD subtypes). The arsenic concentration was measured in a specific section of hair that grew from 3 months before to 3 months after conception. We found a higher hair arsenic concentration in the NTD cases with median (inter-quartile range) of 0.093 (0.025-0.387) μg/g hair than that in the controls with a value of 0.082 (0.030-0.414) μg/g hair. Maternal hair arsenic concentration above its median of the controls was associated with an increased risk of the total NTDs with an adjusted odds ratio (OR) of 1.32 [95% confidence interval (CI): (0.91-1.92)], which was not statistically significant (p = 0.14), although the crude OR without adjusting for the confounders of 1.68 (95% CI: 1.24-2.27; p < 0.001) suggested that hair arsenic is a risk factor of NTDs. There was no dose-response relationship between maternal hair arsenic concentration and the risk of total NTDs. Similar phenomena were found for anencephaly and spina bifida, respectively. Overall, our findings showed that maternal periconceptional arsenic exposure may not significantly contribute to the risk of NTD development in Northern China; other risk factors need to be further examined in future studies.

Organochlorine pesticides in ambient air from the littoral cities of northern China: Spatial distribution, seasonal variation, source apportionment and cancer risk assessment

Concentrations, composition and seasonal variations of organochlorine pesticides (OCPs) in the atmosphere (particulate phase and gaseous phase) at coastal cities in northern China were determined. OCP transport from emission source areas and lifetime excess cancer risks by inhalation exposure to specific OCPs were also investigated. The annual average concentration of total OCPs in gaseous phase ranged from 1.0ng/m³ to 6.3ng/m³, with the peak observed in summer at most sites. Particulate phase concentrations ranged from 29.9pg/m³ to 103.3pg/m³, with the maximum found in the local heating period at most locations. The detection rates of gaseous samples were considerably higher than those of particulate ones. The dominant components included endosulfan (I and II), (α- and γ-) chlordane, pentachlorobiphenyl (PeCB), hexachlorobenzene (HCB), heptachlor, (α-, β- and γ-) hexachlorocyclohexane (HCH), dichloro-diphenyl-trichloroethane (DDT) and their metabolic products. The specific ratios indicated different applications of DDT, technical HCH and endosulfan at most sites. Large differences in compositional profiles occurred in January (typical heating period) and July (representative non-heating period), and diurnal changes in component concentrations may have been influenced by local emission pattern. The potential source contribution function (PSCF) manifested seasonal concentrations of airborne OCPs affected by the input of potential sources in different regions. The emission sources with higher contribution probabilities to the sites were primarily distributed in the surrounding areas. The lifetime excess cancer risks for the local residents by inhalation exposure to specific components were not high, though the potential threat of α-HCH and HCB should be concerned. CAPSULE: Gaseous OCPs reached peak values in summer and dominated relative to particulate (PM₁₀) values; meanwhile, surrounding sources affected air OCP concentrations, and cancer risks of OCPs by inhalation exposure were not high.

Urinary concentration of personal care products and polycystic ovary syndrome: A case-control study

Polycystic ovary syndrome (PCOS) is one of the most common endocrine disorder among females of reproductive age. Many emerging contaminants in personal care products have been confirmed with endocrine disruptive effects. We performed a case-control study to explore the association between the concentrations of certain emerging contaminants (organic UV filters, bisphenol A, and triclosan) and the risk of PCOS. Urine samples were collected from 40 women with PCOS (case group) and 83 healthy women (control group). No significant differences were found in detection rate or total concentrations of analytes in women with PCOS and controls (p > 0.05). In addition, no association was found between certain emerging contaminants and PCOS either in an unadjusted binary logistic regression model or in a model adjusted for potential confounders. However, with stratification according to body mass index, one organic UV filter - octocrylene(OC) was significantly associated with PCOS in women with BMI ≥ 24 (adjusted OR = 1.512, 95% CI: 1.043, 2.191). It's the first time to investigate the association between exposure of organic UV filters and PCOS risk. We conclude that there is positive association between OC and PCOS risk in obese and overweight women.

Association of pesticide exposure with human congenital abnormalities

Human pesticide exposure can occur both occupationally and environmentally during manufacture and after the application of indoor and outdoor pesticides, as well as through consumption via residues in food and water. There is evidence from experimental studies that numerous pesticides, either in isolation or in combination, act as endocrine disruptors, neurodevelopmental toxicants, immunotoxicants, and carcinogens. We reviewed the international literature on this subject for the years between 1990 and 2017. The studies were considered in this review through MEDLINE and WHO resources. Out of the n = 1817 studies identified, n = 94 were reviewed because they fulfilled criteria of validity and addressed associations of interest. Epidemiological studies have provided limited evidence linking pre- and post-natal exposure to pesticides with cancers in childhood, neurological deficits, fetal death, intrauterine growth restriction, preterm birth, and congenital abnormalities (CAs). In this review, the potential association between pesticide exposure and the appearance of some human CAs (including among others musculoskeletal abnormalities; neural tube defects; urogenital and cardiovascular abnormalities) was investigated. A trend towards a positive association between environmental or occupational exposure to some pesticides and some CAs was detected, but this association remains to be substantiated. Main limitations of the review include inadequate exposure assessment and limited sample size. Adequately powered studies with precise exposure assessments such as biomonitoring, are warranted to clarify with certainty the potential association between pesticide exposure and human CAs.

Variations in serum concentrations of selected organochlorines among delivering women in Argentina. The EMASAR study

The EMASAR study is the first study to describe the body burden of OCs in Argentinian women after delivery. In total, 698 maternal serum samples from Salta (n = 498) and Ushuaia (n = 200) were collected in 2011-2012 and analyzed for a total of 7 polychlorinated biphenyls (PCBs) and 12 pesticide-related compounds. Only 11 of the compounds had detection rates above 60% in one or both places. Compared with Ushuaian women, those from Salta exhibited higher lipid-adjusted concentrations of p,p'-DDE, p,p'-DDT, β-HCH, and PCB 118 (p ≤ 0.003), with no differences in concentrations of PCB 153 and 138. After controlling for age, parity and heritage (born in the province or migrated there from other regions of Argentina), concentrations of p,p'-DDE, p,p'-DDT, β-HCH and all PCBs were significantly higher in Salta natives compared with Ushuaia natives or migrants (p ≤ 0.010). No variations between native and migrated Ushuaian women were observed other than for PCB 153 (6.1 versus 8.6 μg kg^-1 lipid, p = 0.022). Age was generally associated positively with the body burden of nearly all OCs and parity negatively so, with p,p'-DDD, o,p'-DDT, and o,p'-DDD residues and α-HCH in Ushuaia being the exceptions. The regional differences in OC concentrations are explained by contrasting domestic sources, historical and current uses, industrial emissions, dietary patterns and lifestyle factors, as well as long-range-transport. The relatively high PCB 118/PCB 180 ratio observed for both Argentinian communities likely reflects the use of technical mixtures with congener-specific composition. In a comprehensive comparison with other countries, the Argentinian OC concentrations were mostly in the lower range. It is concluded that a latitude effect equivalent to that operative in the Arctic region seems unlikely.

A pilot study on the association between rare earth elements in maternal hair and the risk of neural tube defects in north China

Rare earth elements (REEs) have many applications in industry, agriculture, and medicine, resulting in occupational and environmental exposure and concerns regarding REE-associated health effects. However, few epidemiological studies have examined the adverse effects of REEs on pregnancy outcomes. Therefore, this study examined the relationship between the REE concentrations in maternal hair growing during early pregnancy and the risk of neural tube defects (NTDs) in offspring. We included 191 women with NTD-affected pregnancies (cases) and 261 women delivering healthy infants (controls). The cases were divided into three subtypes: anencephaly, spina bifida, and encephalocele. Four REEs in maternal hair were analyzed by inductively coupled plasma-mass spectrometry: lanthanum (La), cerium (Ce), praseodymium (Pr), and neodymium (Nd). A questionnaire was used to collect information about maternal sociodemographic characteristics and dietary habits. The median concentrations of Ce and Pr in the NTD group were higher than those in the control group, whereas there were no significant differences for La and Nd. The adjusted odds ratios (ORs) for the four REE concentrations above the median in the case groups were not significantly > 1. An increasing frequency of the consumption of beans or bean products and fresh fruit was negatively correlated with the four REE concentrations. Our results did not suggest that the concentrations of REEs in maternal hair were associated with the risk of NTDs or any subtype of NTDs in the general population.

Association between titanium and silver concentrations in maternal hair and risk of neural tube defects in offspring: A case-control study in north China

Increasing uses of titanium and silver in various products raise concerns for their potential adverse effects on pregnancy outcomes. We aimed to examine the associations between titanium and silver concentrations in maternal hair growing during the periconception period and the risk of neural tube defects (NTDs) in offspring. Our case-control study recruited 191 women with NTD-affected pregnancies and 261 women delivering healthy infants. Metal concentrations in maternal hair were measured by inductively coupled plasma-mass spectrometry. The adjusted odds ratios (AOR) of titanium concentration above the median were 1.46 (95% confidence interval (CI), 0.99-2.13) for total NTDs and 2.10 (95% CI, 1.12-3.94) for anencephaly, while OR of silver wasn't statistically significant. Titanium concentration was positively correlated with consumptions of vegetables and fruits. Maternal exposure to titanium during the periconception period was associated with an increased NTD risk in offspring, which may be partly mediated through maternal dietary habits.

Levels of folate receptor autoantibodies in maternal and cord blood and risk of neural tube defects in a Chinese population

BACKGROUND

After years of periconceptional folic acid supplementation, the prevalence of neural tube defects (NTDs) remains stable following the remarkable reduction observed immediately after the fortification practice. There is accumulating evidence that folate receptor (FR) autoimmunity may play a role in the etiology of folate-sensitive NTDs.

METHODS

From 2011 to 2013, 118 NTD cases and 242 healthy controls were recruited from a population-based birth defects surveillance system in Northern China. Enzyme-linked immunosorbent assay was used to measure FR autoantibodies in maternal and cord blood. Logistic regression models were used to estimate the odds ratios (OR) and 95% confidence intervals (95% CI).

RESULTS

Plasma FR autoantibodies levels were significantly elevated in mothers of infants with NTDs compared with mothers of healthy controls. Using the lowest tertile as the referent group, 2.20-fold (95% CI, 0.71-6.80) and 5.53-fold increased odds (95% CI, 1.90-16.08) of NTDs were observed for the second and third tertile of immunoglobulin G (IgG), respectively, and the odds of NTDs for each successive tertile of IgM was 0.98 (95% CI, 0.35-2.75) and 3.49 (95% CI, 1.45-8.39), respectively. A dose-response relationship was found between FR autoantibodies levels and risk of NTDs (P < 0.001 for IgG, P = 0.002 for IgM). The same pattern was observed in both subtypes of spina bifida and anencephaly. No significant difference in levels of cord blood FR autoantibodies was observed.

CONCLUSION

Higher levels of FR autoimmunity in maternal plasma are associated with elevated risk of NTDs in a dose-response manner. Birth Defects Research (Part A) 106:685-695, 2016. © 2016 Wiley Periodicals, Inc.

Markers of macromolecular oxidative damage in maternal serum and risk of neural tube defects in offspring

Neural tube defects (NTDs) are among the most common and severe congenital malformations. To examine the association between markers of macromolecular oxidative damage and risk of NTDs, we measured levels of 8-hydroxy-2'-deoxyguanosine (8-OHdG), protein carbonyl (PC), and 8-iso-prostaglandin F2α (8-iso-PGF2α) in maternal serum samples of 117 women with NTD-affected pregnancies and 121 women with healthy term newborns. We found higher levels of 8-OHdG and PC in the NTD group than in the control group; however, we did not observe a statistically significant difference in 8-iso-PGF2α levels between the NTD and the control groups. NTD risk increased with increasing quartiles of 8-OHdG [odds ratio (OR)=1.17; 95% confidence interval (CI) 0.39-3.51; OR=2.19; 95% CI, 0.68-7.01; OR=3.70; 95% CI, 1.30-10.51, for the second, third, and fourth quartile relative to the lowest quartile, respectively; P=0.009], and with increasing quartiles of PC (OR=2.26; 95% CI, 0.66-7.69; OR=3.86; 95% CI, 1.17-12.80; OR=5.98; 95% CI, 1.82-19.66, for the second, third, and fourth quartile relative to the lowest quartile, respectively; P=0.002]. Serum levels of 8-OHdG were higher in women who did not take folic acid supplements during the periconceptional period. These results suggest that oxidative stress is present in women carrying pregnancies affected by NTDs.

Levels of polycyclic aromatic hydrocarbons in maternal serum and risk of neural tube defects in offspring

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous environmental pollutants, and have been reported to be a risk factor for human neural tube defects (NTDs). We investigated the relationship between PAH concentrations in maternal serum and NTD risk in offspring using a case-control study design, and explored the link between PAH concentrations to household energy usage characteristics and life styles. One hundred and seventeen women who had NTD-affected pregnancies (cases) and 121 women who delivered healthy infants (controls) were recruited in Northern China. Maternal blood samples were collected at pregnancy termination or at delivery. Twenty-seven PAHs were measured by gas chromatography-mass spectrometry. The concentrations of 13 individual PAHs detected were significantly higher in the cases than in the controls. Clear dose-response relationships between concentrations of most individual PAHs and the risk of total NTDs or subtypes were observed, even when potential covariates were adjusted for. High-molecular-weight PAHs (H-PAHs) showed higher risk than low-molecular-weight PAHs (L-PAHs). No associations between PAH concentrations and indoor life styles and energy usage characteristics were observed. It was concluded that maternal exposure to PAHs was associated with an increased risk of NTDs, and H-PAHs overall posed a higher risk for NTDs than L-PAHs.