Joint effects of genetic variants and residential proximity to pesticide applications on hypospadias risk

Maternal PM2.5 exposure and hypospadias risk in Chinese offspring: Insights from a nationwide surveillance-based study

Research on the association between maternal PM2.5 exposure and hypospadias risk in male offspring, particularly in highly polluted areas, has been limited and inconsistent. This study leveraged data from China's National Population-based Birth Defects Surveillance System spanning the years 2013 to 2019, and employed sophisticated machine learning models to estimate daily PM2.5 levels and other pollutants for mothers at a 1-km resolution and a 6-km buffer surrounding maternal residences. Multivariate logistic regression analyses were performed to evaluate the relationship between PM2.5 exposure and hypospadias risk. For sensitivity analyses, stratification analysis was conducted, and models for one-pollutant and two-pollutants, as well as distributed lag nonlinear models, were constructed. Of the 1194,431 boys studied, 1153 cases of hypospadias were identified. A 10 μg/m3 increase in maternal PM2.5 exposure during preconception and the first trimester was associated with an elevated risk of isolated hypospadias, with Odds Ratios (ORs) of 1.102 (95% CI: 1.023-1.188) and 1.089 (95% CI: 1.007-1.177) at the 1-km grid, and 1.122 (95% CI: 1.034-1.218) and 1.143 (95% CI: 1.048-1.246) within the 6-km buffer. Higher quartiles of PM2.5 exposure were associated with increased odds ratios compared to the lowest quartile. These findings highlight a significant association between PM2.5 exposure during the critical conception period and an elevated risk of isolated hypospadias in children, emphasizing the need for targeted interventions to reduce PM2.5 exposure among expectant mothers.

Evaluating the accuracy of satellite-based methods to estimate residential proximity to agricultural crops

BACKGROUND

Epidemiologic investigations increasingly employ remote sensing data to estimate residential proximity to agriculture as a means of approximating individual-level pesticide exposure. Few studies have examined the accuracy of these methods and the implications for exposure misclassification.

OBJECTIVES

Compare metrics of residential proximity to agricultural land between a groundtruth approach and commonly-used satellite-based estimates.

METHODS

We inspected 349 fields and identified crops in current production within a 0.5 km radius of 40 residences in Idaho. We calculated the distance from each home to the nearest agricultural field and the total acreage of agricultural fields within a 0.5 km buffer. We compared these groundtruth estimates to satellite-derived estimates from three widely used datasets: CropScape, the National Land Cover Database (NLCD), and Landsat imagery (using Normalized Difference Vegetation Index thresholds).

RESULTS

We found poor to moderate agreement between the classification of individuals living within 0.5 km of an agricultural field between the groundtruth method and the comparison datasets (53.1-77.6%). All satellite-derived estimates overestimated the acreage of agricultural land within 0.5 km of each home (average = 82.8-148.9%). Using two satellite-derived datasets in conjunction resulted in substantial improvements; specifically, combining CropScape or NLCD with Landsat imagery had the highest percent agreement with the groundtruth data (92.8-93.8% agreement).

SIGNIFICANCE

Residential proximity to agriculture is frequently used as a proxy for pesticide exposure in epidemiologic investigations, and remote sensing-derived datasets are often the only practical means of identifying cultivated land. We found that estimates of agricultural proximity obtained from commonly-used satellite-based datasets are likely to result in exposure misclassification. We propose a novel approach that capitalizes on the complementary strengths of different sources of satellite imagery, and suggest the combined use of one dataset with high temporal resolution (e.g., Landsat imagery) in conjunction with a second dataset that delineates agricultural land use (e.g., CropScape or NLCD).

The Alberta Congenital Anomalies Surveillance System: a 40-year review with prevalence and trends for selected congenital anomalies, 1997-2019

INTRODUCTION

Current published long-term provincial or territorial congenital anomaly data are lacking for Canada. We report on prevalence (per 1000 total births) and trends in 1997-2019, in Alberta, Canada, for selected congenital anomalies. Associated risk factors are also discussed.

METHODS

We used data from the Alberta Congenital Anomalies Surveillance System (ACASS) to calculate the prevalence and perform chi-square linear trend analyses.

RESULTS

From 1997 to 2019, the overall prevalence of neural tube defects was stable, at 0.74 per 1000 total births. The same was true for spina bifida (0.38), orofacial clefts (1.99), more severe CHDs (transposition of the great arteries, 0.38; tetralogy of Fallot, 0.33; and hypoplastic left heart syndrome, 0.32); and gastroschisis (0.38). Anencephaly, cleft palate and anorectal malformation significantly decreased with a prevalence of 0.23, 0.75 and 0.54 per 1000 total births, respectively. Significantly increasing trends were reported for anotia/microtia (0.24), limb reduction anomalies (0.73), omphalocele (0.36) and Down syndrome (2.21) and for hypospadias and undescended testes (4.68 and 5.29, respectively, per 1000 male births).

CONCLUSION

Congenital anomalies are an important public health concern with significant social and societal costs. Surveillance data gathered by ACASS for over 40 years can be used for planning and policy decisions and the evaluation of prevention strategies. Contributing genetic and environmental factors are discussed as is the need for continued surveillance and research.

Pesticide Exposure in Relation to the Incidence of Abnormal Glucose Regulation: A Retrospective Cohort Study

Diabetes and prediabetes (called abnormal glucose regulation (AGR)) are adverse health effects associated with exposure to pesticides. However, there are few epidemiological studies on the relationship between pesticide use and the incidence of AGR. We examined the causal relationship between pesticide use and AGR incidence in a rural population using data from a Korean Farmers’ Cohort study of 1076 participants. Poisson regression with robust error variance was used to calculate the relative risks (RR) and 95% confidence intervals (CI) to estimate the relationship between pesticide exposure and AGR. The incidence of AGR in the pesticide-exposed group was 29.1%. Pesticide use increased the RR of AGR (RR 1.32, 95% CI 1.03–1.69). We observed a low-dose effect related to exposure of pesticides to AGR and a U-shaped dose–response relationship in men. Pesticide exposure is related to the incidence of AGR, and the causal relationship differs between men and women.

Development of an analytical method based on solid-phase extraction and LC-MS/MS for the monitoring of current-use pesticides and their metabolites in human urine

Pyrethroids, organophosphorus pesticides and fipronil have been listed as priority chemicals in human biomonitoring studies because of their wide use and potential health effects in humans. The determination of 13 pesticides, including pyrethroids (deltamethrin, cypermethrin, permethrin, cyfluthrin, bifenthrin), organophosphorus (chlorpyrifos, chlorpyrifos-methyl, and malathion), fipronil, neonicotinoids (imidacloprid, acetamiprid and thiacloprid) and triazole (prothioconazole), together with 13 corresponding metabolites in human urine samples was achieved by solid-phase extraction and analysis by liquid chromatography coupled to tandem mass spectrometry. All targeted compounds, except malathion dicarboxylic acid, were measured with a mean within-accuracy (n = 5) of 71%-114% (RSD: 1%-14%) and between-run (n = 15) accuracy of 80%-118% (RSD: 2%-14%). Limits of quantitation of the targeted analytes ranged from 0.1 to 16 pg/mL. The detection result of urine samples from 25 volunteers indicated that the detection frequencies of 3,5,6-trichloro-2-pyridinol (median: 448 pg/mL), 6-chloropyridine-3-carboxylic acid (median: 193 pg/mL), 2-methyl-3-phenylbenzoic acid (median: 181 pg/mL), 3-phenoxybenzoic acid (median: 99 pg/mL), 2-isopropyl-6-methyl-4-pyrimidinol (median: 77 pg/mL), cyfluthrin (median: 59 pg/mL), cis-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylic acid (cis-DCCA, median: 53 pg/mL), trans-DCCA (median: 25 pg/mL), prothioconazole (median: 21 pg/mL), imidacloprid (median: 7 pg/mL), and prothioconazole-desthio (median: 1 pg/mL) were > 50%. The obtained results show that the validated method is suitable for the human biomonitoring of these current-use pesticides and their metabolites.

Prevalence rates study of selected isolated non-Mendelian congenital anomalies in the Hutterite population of Alberta, 1980-2016

A study of the prevalence rates for selected isolated non-Mendelian congenital anomalies in the Hutterite Brethren of Alberta, Canada was undertaken to further examine longitudinal data in this isolated community that was last reported in 1985 (Lowry et al., 1985), although there are numerous publications on recessive disorders (Boycott et al., 2008; Triggs-Raine et al., 2016). Cases were ascertained from the Alberta Congenital Anomaly Surveillance System for the years 1997-2016. Since our initial results showed some surprising findings in the Hutterite Brethren, such as zero cases of spina bifida, cleft lip and palate, gastroschisis, and omphalocele, and a significant excess of cases with hypospadias, we extended the study to prior years (1980-1996) for selected anomalies. For the extended study period (1980-2016), there was a significant increased prevalence of hypospadias, tetralogy of Fallot and tricuspid atresia in the Hutterite population, and although not statistically significant, zero cases of cleft lip with cleft palate, gastroschisis and omphalocele were confirmed. Further research is needed to determine the precise effects of rural environmental exposures, lifestyle factors, and genetic associations for selected multifactorial congenital anomalies.

Periconceptional exposure to air pollution and congenital hypospadias among full-term infants

BACKGROUND

Evidence regarding whether prenatal exposure to air pollution increases the risk of hypospadias remains limited. The aim of the study is to evaluate the association between exposure to ambient air pollution during early pregnancy and the incidence of hypospadias.

METHODS

We conducted a 1:10 case-control study using the Taiwanese Birth Registry database. Male full-term infants reported to have hypospadias were defined as cases, and controls were randomly selected from male full-term infants without any congenital anomaly. The monthly average of ambient air pollutants, including PM₁₀, PM_2.5, PM_2.5-10, NO₂, NOx, O₃, and O₃ 8-h maximum, from 3 months before conception to 6 months post conception was retrieved from air quality monitoring stations and interpolated to the level of township using the kriging method. Multivariable logistic regression models were utilized to evaluate the associations.

RESULTS

A total of 200 hypospadias cases, with 2000 healthy controls sampled, were reported during 2007-2014. The results revealed that PM_2.5 exposure during the first 3 months after conception (odds ratio [OR] = 1.29, 95% confidence interval [CI]: 1.01-1.65, per interquartile range [IQR] = 15.6 μg/m³) and O₃ exposure during the first month after conception (OR = 1.40, 95% CI: 1.08-1.82, per IQR = 8.0 ppb) were associated with a higher incidence of hypospadias.

CONCLUSIONS

The results of the study suggest that early gestational exposure to ambient air pollution increases the risk of hypospadias among full-term infants.

Pesticide exposures for residents living close to agricultural lands: A review

BACKGROUND

Residents living close to agricultural lands might be exposed to pesticides through non-occupational pathways including spray drift and volatilization of pesticides beyond the treated area.

OBJECTIVE

This review aimed to identify and analyze scientific literature measuring pesticide exposure in non-farmworker residents living close to agricultural lands, and to suggest practical implications and needs for future studies.

METHODS

A review was performed using inclusion criteria to identify original articles of interest published between 2003 and 2018.

RESULTS

From the 29 articles selected in this review, 2 belonged to the same study and were grouped, resulting in a total of 27 studies. Seven studies assessed exposure to pesticides using environmental samples, 13 collected biological samples and 7 analyzed both. Nine studies included a reference group of residents living far from agricultural lands while 11 assessed the influence of the spraying season or spray events on pesticide exposures. Studies included in this review provide evidence that residents living near to agricultural lands are exposed to higher levels of pesticides than residents living further away.

DISCUSSION AND CONCLUSION

This review highlights that the following study design characteristics may be more appropriate than others to measure pesticide spray drift exposure in non-farmworker residents living close to agricultural lands: inclusion of a non-agricultural control group, collection of both biological and environmental samples with repeated sampling, measurements at different periods of the year, selection of numerous study sites related to one specific crop group, and measurements of pesticides which are specific to agricultural use. However, few studies to date incorporate all these characteristics. Additional studies are needed to comprehensively measure non-occupational pesticide exposures in this population in order to evaluate health risks, and to develop appropriate prevention strategies.

Residential proximity to greenhouse agriculture and neurobehavioral performance in Ecuadorian children

BACKGROUND

Children living near greenhouse agriculture may have an increased risk of pesticide exposure due to drift or direct contact with pesticide-treated areas. However, little is known about whether this increased potential for chronic exposure may impair their neurodevelopment.

METHODS

We examined 307 children aged 4-9 years, living in agricultural communities in Ecuador (ESPINA study). The two exposures calculated were residential distance from the nearest flower plantation perimeter and flower plantation surface area within 100 m of homes. Five neurobehavioral domains were assessed: Attention/Inhibitory Control, Memory/Learning, Visuospatial processing and Sensorimotor (higher values reflect better performance). Low scores were defined according to the test's cut-offs. Models were adjusted for demographic, socio-economic and growth variables.

RESULTS

The mean (SD) residential distance to the nearest flower plantation was 446 m (344). Living 100 m closer to crops was associated with increased odds (OR [95% CI]) of low scores in the domains of Memory/Learning (1.24 [1.05, 1.46]) and Language (1.09 [1.00, 1.19]). Associations were strongest among children living within 50 m, having significantly lower scores in Language (-1.28 which is ~50% of a SD [-2.50, -0.06]), Attention/Inhibitory Control (-1.24 units, [-2.45, -0.04]), and Memory/Learning (-0.91, [-1.99, 0.17]), compared to children living farther than 500 m. Analyses of areas of flower crops near homes concurred with these findings.

CONCLUSIONS

Close residential proximity to greenhouse floricultural crops was associated with adverse neurobehavioral performance in Attention/Inhibitory Control, Language and Memory/Learning among children. This highlights the importance of reducing pesticide drift from plantations to nearby homes.

Molecular genetics of hypospadias and cryptorchidism recent developments

During the last decade, a tremendous amount of work has been devoted to the study of the molecular genetics of isolated hypospadias and cryptorchidism, two minor forms of disorders of sex development (DSD). Beyond the genes involved in gonadal determination and sex differentiation, including those underlying androgen biosynthesis and signaling, new genes have been identified through genome-wide association study and familial clustering. Even if no single genetic defect can explain the whole spectrum of DSD, these recent studies reinforce the strong role of the genetic background in the occurrence of these defects. The timing of signaling disruption may explain the different phenotypes.

Environmental Health Tracking Improves Pesticide Use Data to Enable Research and Inform Public Health Actions in California

Pesticides have adverse impacts on the environment and public health. In response to growing public concern over these impacts, California implemented the Pesticide Use Reporting (PUR) program in 1990. The PUR program is widely recognized as the world's most comprehensive pesticide reporting system, and its pesticide application records are highly detailed. However, the complexity and volume of PUR data require a level of data skills and resources beyond many government agencies, public health professionals, and community stakeholders. Over the past decade, the California Environmental Health Tracking Program has undertaken multiple strategies to make PUR data more accessible, understandable, and useful to a diversity of data users. Three specific efforts are described in detail-the Pesticide Linkage Service, the Pesticide Mapping Tool, and a policy-relevant analysis on pesticide use near schools-as are their impacts on environmental and public health research, community outreach and education, and policy change.

A population-based study of prevalence trends and geospatial analysis of hypospadias and cryptorchidism compared with non-endocrine mediated congenital anomalies

INTRODUCTION

Several reports have suggested an increase in the prevalence of hypospadias and cryptorchidism over the last few decades. Endocrine disruption caused by exposure to environmental chemicals has been postulated as a possible cause.

OBJECTIVES

The objectives of our study were: 1) to determine whether the prevalence of hypospadias and cryptorchidism is increasing compared with other congenital anomalies not known to be mediated by endocrine factors; and 2) to perform a geospatial analysis of these congenital malformations looking for clustering that could offer insight into environmental risk factors.

MATERIAL AND METHODS

Data were obtained from the Nova Scotia ATLEE Perinatal Database containing the perinatal records of all live births in Nova Scotia, Canada since 1988. Records from 1988 to 2013 defined the study cohort. Overall prevalence rates and prevalence trends by year were calculated for hypospadias, cryptorchidism, gastroschisis, and clubfoot. County of residence was collected and spatial autocorrelation testing for clustering was performed for each of the congenital anomalies.

RESULTS

There were 258,147 live births during the study period. Overall prevalence rates for the four malformations over the study period were: hypospadias 78 per 10,000 male births, cryptorchidism 75 per 10,000 male births, clubfoot 24 per 10,000 total births, and gastroschisis 4 per 10,000 total births. Incidence rate ratios per year for hypospadias, cryptorchidism, clubfoot, and gastroschisis were 1.00 (0.99-1.01), 0.99 (0.98-1.00), 0.98 (0.97-0.99), and 1.04 (1.04-1.07), respectively. During the study period, the prevalence rates in the region were unchanged for hypospadias, slightly reduced for cryptorchidism and clubfoot, and rising for gastroschisis (Figure). Spatial autocorrelation testing revealed statistically significant clustering for hypospadias (p = 0.03) and cryptorchidism (p = 0.03), while no spatial autocorrelation was observed for the other malformations.

DISCUSSION

Contrary to previous studies we show that hypospadias and cryptorchidism prevalence rates are not increasing over time in our region. Nonetheless, rates for these conditions in our area are high compared with other regions of the world. Local clustering of these congenital anomalies without clustering of the control, non-endocrine mediated congenital malformations supports a possible unique spatial distribution associated with environmental exposure. The hotspots identified for hypospadias and cryptorchidism are associated with intense agricultural activity.

CONCLUSIONS

Our study found no increase in hypospadias and cryptorchidism prevalence over a 26-year period compared with other congenital anomalies not known to be associated with endocrine factors. Geospatial analysis supports high clustering for hypospadias and cryptorchidism in areas of intense agricultural activity.

Maternal Exposure to Domestic Hair Cosmetics and Occupational Endocrine Disruptors Is Associated with a Higher Risk of Hypospadias in the Offspring

Pregnant women are exposed to various chemical products at home and at work. Some of these products contain endocrine-disrupting chemicals (EDCs) such as cosmetics, pesticides, industrial chemicals, heavy metals, plastics or medications that could alter sexual differentiation and increase the risk of hypospadias. We evaluated maternal occupational and household exposures that could constitute risk factors for hypospadias. From 2011 to 2014, we enrolled 57 full-term newborns with hypospadias and three randomly selected controls per case (162 control newborns), matched for gestational age, from 11 maternity units in Picardy, France. Neonatal and parental data were collected at birth (personal characteristics, maternal lifestyle, and medical history). Maternal occupational exposure was assessed by a job-exposure matrix for EDCs from a job history questionnaire completed by mothers. Odds ratios (OR) and 95% confidence intervals (CI) were calculated with univariate and multivariable logistic regression, and adjusted for relevant covariates. Multivariate analysis showed a strong association between hypospadias and potential maternal occupational exposure to EDCs and maternal household use of hair cosmetics (OR 6.1, 95% CI: 1.1–34.9; OR: 9.6, 95% CI: 1.4–66.1, respectively). Our results suggest that maternal occupational exposure to EDCs is a risk factor for hypospadias and suggests a possible influence of household use of hair cosmetics during early pregnancy on the incidence of hypospadias in the offspring. A larger study with more accurate exposure assessment should evaluate the impact of EDCs in hair cosmetics on the incidence of hypospadias.