Petroleum and Chlorinated Solvents in Meconium and the Risk of Hypospadias: A Pilot Study

Hypothesis-driven weight of evidence evaluation indicates ethylbenzene lacks endocrine disruption potential by EATS pathways

Ethylbenzene (EB) was placed on List 2 for Tier 1 endocrine screening in the U.S. EPA's two-tiered Endocrine Disruptor Screening Program (EDSP) and was scheduled for evaluation under TSCA. Results of toxicology studies on EB were used to evaluate estrogen, androgen, thyroid, and steroidogenic (EATS) endpoints by a Weight of Evidence (WoE) methodology, as required by U.S. EPA and OECD guidelines for evaluating a chemical's endocrine disruptive potential. The WoE method involved problem formulation, systematic literature search and selection, data quality evaluation, relevance weighting of endpoint data, and application of specific interpretive criteria. Data on EB were sufficient to assess its effects on endpoints that would be expected to respond to chemicals that operate via EATS modes of action (MoAs) in various screening assays (Tier 1) and toxicity tests (Tier 2) that evaluate reproduction, development, and sub-chronic and chronic toxicity. In those studies, EB produced a pattern of responses inconsistent with the responses that would be expected for hormones and chemicals known to operate via EATS MoAs. Endocrine-sensitive endpoints that respond to EB administration generally do so only at dose levels above its kinetic maximum dose, indicating a lack of relevance to potential effects at lower dose levels in either the test species or humans. This comprehensive WoE evaluation demonstrates that EB lacks the potential to exhibit endocrine disruptive properties and cannot be deemed an endocrine disruptor or potential endocrine disruptor. Because this WoE evaluation was based largely on Tier 2-level studies of the type considered by the U.S. EPA and OECD to be more definitive than results of Tier 1 EDSP screening results, no additional useful information would be obtained by subjecting EB to further endocrine screening. As such, further endocrine screening of EB would be unjustified from animal welfare perspectives. This analysis supports a regulatory decision to halt further testing of EB for endocrine disruption unless unique and compelling data to the contrary arise. See also the graphical abstract(Fig. 1).

The association of prenatal volatile organic compounds exposure and newborn anthropometrics: A cross-sectional study

BACKGROUND

Several studies have associated prenatal exposure to volatile organic compounds (VOCs) with adverse health outcomes among newborns. However, little is known about the associations of VOCs at relatively low concentrations with newborn outcomes. Hence, this study aimed to investigate the potential associations between prenatal exposure to VOCs and VOC mixtures with newborn anthropometric measures.

METHODS

In this cross-sectional study, 883 mother-term infant pairs who lived in urban areas in Israel and were admitted to the delivery rooms of two major hospitals between 2016 and 2020 were recruited. Associations between VOC metabolites detected in maternal urine samples on the day of delivery with weight, length, and head circumference at birth were estimated using single-exposure linear models and weighted quantile sum (WQS) approach.

RESULTS

Toluene, ethylbenzene/styrene, and xylene metabolites were detected in most samples at levels comparable to OECD populations. In male newborns, higher levels of phenylglyoxylic acid (PGA), a metabolite of ethylbenzene/styrene, were associated with lower birth weight (β = -0.08, 95% CI: 0.14, -0.01; P = 0.03). WQS models suggested PGA as the most prominent contributor to this association.

CONCLUSION

This study suggests that moderate exposure to ethylbenzene/styrene may be associated with reduced birth weight in male newborns. The sex-specific finding requires further research for the potential endocrine-disrupting mechanisms of these compounds. While the effect size was small, these results highlight the need to better understand the associations of frequent VOC exposures in levels similar to those common in OECD countries with fetal and child development.

Review of non-invasive biomarkers as a tool for exposure characterization in human health risk assessments

Blood and urine are historically the most frequent matrices used for measuring chemical levels in human biomonitoring studies. As biomonitoring programs are refreshed, consideration of specific priority substances and specific population targets provide opportunities for inclusion of alternative non- or minimally invasive matrices. This review describes methods used in health risk assessment to characterize exposure and risk based upon biomarkers from noninvasive matrices other than urine or blood, including human milk, hair, fingernails, toenails, exhaled breath, deciduous teeth, sweat, semen, meconium, and feces. Illustrative examples of these methods relevant to chemical management are provided. This review suggests that, although these alternative noninvasive biomarkers are not frequently used in human health risk assessment at present, these biomarkers may prove useful in (1) characterizing exposure and health risk in vulnerable populations, (2) cumulative risk assessments, and (3) community-based risk assessments, depending upon the substance of concern. To incorporate alternative noninvasive biomarkers into human health risk assessments with confidence, more research is needed to improve our knowledge of the relationships between external dose, internal dose, and biologic consequent effects in matrices other than blood and urine.

Parental occupational exposure to solvents and risk of developing testicular germ cell tumors among sons: a French nationwide case-control study (TESTIS study)

OBJECTIVES

The etiology of testicular germ cell tumors (TGCT) is suspected to be related to prenatal environmental risk factors. Some solvents have potential endocrine disrupting or carcinogenic properties and may disrupt male genital development in utero. The aim of this study was to examine the association between parental occupational exposure to solvents and TGCT risk among their offspring.

METHODS

A French nationwide case-control study, TESTIS included 454 TGCT cases and 670 controls frequency-matched on region and 5-year age strata. Participants were interviewed via telephone and provided information on parental occupations at birth. Job-exposure matrices (JEM) developed in the French Matgéné program were used to assign exposure to five petroleum-based solvents, five solvents or groups of oxygenated solvents, and five chlorinated solvents. Odds ratios (OR) for TGCT and 95% confidence intervals (CI) were estimated using conditional logistic regression, adjusting for TGCT risk factors.

RESULTS

Occupational exposure to at least one solvent during the year of their son's birth was 41% among fathers and 21% among mothers. Paternal exposure to at least one solvent showed OR 0.89 (95% CI 0.68-1.15). Exposure to perchloroethylene (OR 1.41, 95% CI 0.55-3.61), methylene chloride (OR 1.13, 95% CI 0.54-2.34) and diesel/kerosene/fuel oil (OR 1.17, 95% CI 0.80-1.73) disclosed OR >1 but with low precision. Our results suggest a possible modest increase in non-seminoma risk for sons whose fathers were highly exposed to trichloroethylene (OR 1.44, 95% CI 0.79-2.63). Maternal exposure to at least one solvent showed OR 0.90 (95% CI 0.65-1.24). When stratifying by birth year, men born in the 1970s experienced an increased TGCT risk following maternal exposure to fuels and petroleum-based solvents (OR 2.74, 95% CI 1.11-6.76).

CONCLUSION

Overall, no solid association was found between parental occupational exposure to solvents and TGCT risk. The association found with maternal occupational exposure to fuels and petroleum solvents among older men needs further investigation.

Current perspectives in hypospadias research: A scoping review of articles published in 2021 (Review)

Hundreds of papers are written about hypospadias every year referring to all aspects of the pathology, being one of the most common congenital malformations. The present study conducted a scoping review of articles published in 2021 to present the main issues and summarize current perspectives and achievements in the field. It searched for the keyword 'hypospadias' in the three most popular databases (PubMed, Scopus and Web of Science). After the analysis of the publications, they were categorized into different domains. The present review was performed respecting the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMA ScR) guidelines. A total of 284 articles were included. These were published in 142 different journals. The most accessed was the Journal of Paediatric Urology with 54 articles. The main identified domains were related to surgical techniques, postoperative care, complications, anesthesia, anatomical factors, genetics, environmental factors, endocrinology, associated malformations, questionnaires and recommendations, management, biological materials, animal models, retrospective studies of centers, social media, bibliometrics, small gestational age, neoplasm, or fertility. Promising modifications of existing surgical techniques were presented with improved outcomes for both the proximal and distal types of hypospadias. Relevant anatomical and etiological, and also genetic factors were clarified. Aspects of the peri- and postoperative management referring to the antibiotherapy, analgesia, dressing techniques, and the future use of novel bioengineering agents to prevent, reduce or treat the occurring complications were discussed.

Maternal environmental, occupational, and urinary metabolite levels of benzene compounds and their association with congenital heart diseases in offspring: a case‒control study in China

The conclusions about the association of maternal pregnancy environment, occupation, and benzene compounds with fetal CHD are not entirely consistent. Eight hundred seven CHD cases and 1008 controls were included in this study. All occupations were classified and coded against the Occupational Classification Dictionary of the People's Republic of China (2015 version). Logistic regressions were used to explore the correlation among environmental factors, occupation types, and CHDs in offspring. We found that living near public facilities and having exposure to chemical reagents and hazardous substances were significant risk factors for CHDs in offspring. We found that offspring of mothers who worked in agriculture and similar work during pregnancy suffered from CHD. The risk of all CHDs in the offspring of pregnant women working in production manufacturing and related work was significantly higher than that in unemployed pregnant women, the risk was also observed in 4 subtypes of CHDs. We compared the concentrations of the five metabolite (MA, mHA, HA, PGA, and SPMA) levels of benzene compounds in the urine of mothers in case and control groups and found no significant differences. Our study suggests that maternal exposure during pregnancy and certain environmental and occupational conditions are risk factors for CHD in offspring, but did not support an association between concentrations of metabolites of benzene compounds in the urine of pregnant women and CHDs in their offspring.