When preparing for pregnancy, you focus only on whether you use computers, take medications, or undergo chest X-rays—but pay far too little attention to these substances!

Where do these pesticides ultimately end up? Are their production volumes increasing or decreasing? Don’t ask me—I don’t know the answers. What I do know is: perhaps controlling what we eat matters even more. Chemical Products and Human Health Some people ask: Why do two people living in the same environment—and even eating the same food—develop different diseases? Why do their pregnancy experiences differ? This is because: • Individual tolerance levels vary; • Exposure levels (duration and dose) differ; • Baseline health status varies; • Subjective mental states and objective stress levels differ; • Sex and genetic makeup differ (non-modifiable factors). … Let’s stop overthinking these variables. Some facts are undeniable: • Persistent organic pollutants (POPs) and metals have been detected in human breast milk worldwide [3][4]. • Specifically, organochlorine pesticides, polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs), polybrominated diphenyl ethers (PBDEs), and metals have all been found in breast milk. In countries where these chemicals have been banned or otherwise regulated, concentrations of organochlorine pesticides, PCBs, and dioxins in breast milk have declined over recent decades. Conversely, PBDE levels are rising. Regional differences, as well as historical and current local production patterns, influence breast milk concentrations of these substances. Diet—especially fish consumption—is the primary factor affecting POP levels in breast milk. • In Europe and North America, concerns are mounting that the next generation is the 'contaminated generation'—due to chemical exposures before and during pregnancy [5]. On average, every pregnant woman in the U.S. is exposed to ≥43 distinct chemicals. • Exposure to such chemicals at any life stage—regardless of sex—can cause adverse reproductive health outcomes. Examples include: • Prenatal exposure to certain pesticides increases childhood cancer risk; • Adult male exposure to insecticides is associated with altered semen quality, infertility, and prostate cancer; • Postnatal exposure to certain pesticides disrupts all developmental stages of female reproductive function—including puberty, menstruation and ovulation, fertility and fecundity, and menopause. (After learning that sea cucumbers were raised using dichlorvos—an organophosphate pesticide—do you still think pesticides are distant from your daily life? In the past, only rural farming mothers encountered pesticides; today, nearly everyone is exposed.) • Endocrine-disrupting chemicals interfere with hormone signaling, homeostasis, and developmental processes. These include diverse pesticides, plastics, industrial chemicals, and fuels. • Many industrial chemicals impair thyroid function (e.g., again, PBDEs). A few illustrative examples: Polybrominated Diphenyl Ethers (PBDEs) PBDEs are widely used flame retardants. (For readers interested in the original source of the information shown in the accompanying image, please search for the cited references. If the text in the image is difficult to read, try copying the image into WeChat and using its built-in translation feature.) PBDEs are present in numerous electronic and electrical appliances, automated control equipment, construction materials, textiles, furniture, insulating oils, heat-transfer fluids, lubricants—and also serve as additives in many industrial products, including resins, rubber, adhesives, paints, carbonless copy paper, ceramic glazes, fire retardants, pesticide synergists, and dye dispersants.

PFAS Are Universally Detected in Pregnant Women! A U.S. Cohort Study of 3,000 Individuals: How Do Race, Education Level, and Diet Influence Exposure Levels?

01. Literature Summary Title: Sociodemographic Predictors of PFAS Exposure Among a Combined Sample of U.S. Pregnant Women: An Environmental Influences on Child Health Outcomes (ECHO) Public-Use Dataset Analysis Journal: Journal of Exposure Science & Environmental Epidemiology Publication Date: December 15, 2025 02. Background Per- and polyfluoroalkyl substances (PFAS) comprise thousands of synthetic compounds characterized by strong carbon–fluorine bonds, rendering them highly persistent and resistant to degradation. Since the 1940s, they have been widely used across industrial and consumer applications due to their heat resistance and chemical stability. PFAS persist strongly in the environment and exhibit human half-lives ranging from 1.5 to 13 years. Even at background population exposure levels, PFAS have been linked to reduced vaccine antibody responses, fetal growth restriction, elevated serum cholesterol, and increased liver enzyme levels. Although production of traditional long-chain PFAS has been phased out—leading to declining concentrations of some long-chain PFAS in the general population—these compounds can cross the placenta, causing in utero exposure, and are also transferred to infants via breastfeeding. Given that pregnancy and early life represent critical windows of development, PFAS exposure during these periods warrants particular concern. In the U.S., primary PFAS exposure sources include diet (especially seafood such as fish) and consumer product use. Prior studies have documented disparities in PFAS exposure across racial, ethnic, and geographic groups. However, research specifically examining sociodemographic predictors of PFAS exposure among pregnant women remains scarce—particularly analyses leveraging the publicly available dataset from the U.S. National Institutes of Health’s Environmental Influences on Child Health Outcomes (ECHO) Consortium (DASH). This dataset integrates data from 12 independent cohorts but includes limited detection of less commonly measured PFAS congeners. To address this gap, the present study analyzes a nationally representative sample of U.S. pregnant women, aiming to identify populations experiencing disproportionate PFAS exposure risk. 03. Study Design Data were drawn from the U.S. ECHO program’s DASH public-use dataset. After excluding records with missing results or detection-limit flags, retaining only the most sensitive (i.e., lower detection limit) measurements when duplicates existed, and computing weighted means for multiple samples per participant (to adjust for variance differences across gestational timepoints), the final analytic dataset included measurements for 14 PFAS compounds. Seven PFAS with detection rates ≥50% were analyzed as continuous variables. Using R software’s ‘mice’ package, multiple imputation by chained equations was applied to values below the limit of detection (LOD), incorporating covariates including race, ethnicity, maternal education level, age, cohort, parity, gestational week at sampling, and year of sampling. Results from multiple imputed datasets were pooled to minimize statistical bias. The remaining seven PFAS—each with detection rates <50%—were analyzed as binary variables (‘below LOD’ vs. ‘≥LOD’). Additional covariates—including pre-pregnancy BMI, weekly fish intake, and history of breastfeeding—were included to control for potential confounding effects on PFAS exposure levels.

Large Study Shows Pregnant People in the US Exposed to Numerous Common Chemicals

Jun 18, 2026

A large NIH study analyzed 5,318 urine samples, finding widespread exposure to 113 chemicals among pregnant Americans. Results highlight potential birth outcome impacts across ten chemical classes including pesticides and plasticizers.

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2026-06-18

Large Study Shows Pregnant People in the US Exposed to Numerous Common Chemicals

Large Study Shows Pregnant People in the US Exposed to Numerous Common Chemicals

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