{"id":40040,"date":"2025-10-30T00:01:11","date_gmt":"2025-10-30T04:01:11","guid":{"rendered":"https:\/\/beyondpesticides.org\/dailynewsblog\/?p=40040"},"modified":"2025-10-30T11:42:35","modified_gmt":"2025-10-30T15:42:35","slug":"hyperactive-behavior-in-preschoolers-linked-to-endocrine-disrupting-chemical-exposure","status":"publish","type":"post","link":"https:\/\/beyondpesticides.org\/dailynewsblog\/2025\/10\/hyperactive-behavior-in-preschoolers-linked-to-endocrine-disrupting-chemical-exposure\/","title":{"rendered":"Hyperactive Behavior in Preschoolers Linked to Endocrine Disrupting Chemical Exposure"},"content":{"rendered":"

(<\/span>Beyond Pesticides<\/span><\/i>, October 29, 2025) A study published in <\/span>Environment International<\/span><\/i><\/a> evaluates residues of individual and mixtures of endocrine-disrupting chemicals (EDCs), including pesticides, and finds an association between exposure and hyperactive behavior in children. The researchers evaluated urine samples from over 800 preschoolers, identifying and statistically analyzing concentrations of 22 EDCs, and finding that nine of these chemicals are significantly associated with hyperactivity trajectories and EDC mixtures are positively associated with hyperactive behavior, noting the strongest association in girls.<\/span>\u00a0<\/span><\/p>\n

\u201cThe current study indicates the adverse health effects of exposure to mixtures of EDCs among preschoolers, and suggests gender specificity in these effects,\u201d the researchers state. They continue, \u201cThis highlights the importance of focusing on multi-pollutant exposure in early childhood.\u201d<\/span>\u00a0<\/span><\/p>\n

Study Importance<\/span><\/b>\u00a0<\/span><\/p>\n

\u201cAttention-deficit\/hyperactivity disorder (ADHD) <\/span>is a common neurodevelopmental disorder in children, which has become one of the main factors leading to the burden of disease in children and adolescents worldwide.\u201d The authors continue: \u201cIts core symptoms are high levels of inattention and\/or hyperactivity\/impulsivity during the preschool period. A meta-analysis showed that the overall prevalence of ADHD in children in China over the past 15 years was as high as 6.2%, and has been increasing over recent years.\u201d<\/span>\u00a0<\/span><\/p>\n

In comparison, according to the <\/span>Centers for Disease Control and Prevention<\/span><\/a> (CDC), data from 2022 suggests that in the U.S., an estimated 7 million (11.4%) children aged 3\u201317 years have ever been diagnosed with ADHD, based on a national survey of parents. <\/span>\u00a0<\/span><\/p>\n

Beyond Pesticides has <\/span>previously reported<\/span><\/a> that children are susceptible and vulnerable to exposure to harmful contaminants, including EDCs and pesticides. <\/span>Children face much higher hazards<\/span><\/a> than adults from exposure, with disproportionate risks due to their small size and developing organ systems, propensity to crawl and play near the ground, tendency for frequent hand-to-mouth motion, and greater intake of air and food relative to body weight. As shared in the <\/span>Children and Pesticides Don\u2019t Mix<\/a><\/em> fact sheet, studies show children\u2019s developing organs create \u201cearly windows of great vulnerability\u201d during which exposure to pesticides can cause great damage.<\/span>\u00a0<\/span><\/p>\n

With the ubiquitous use of chemicals in commonly used consumer products and throughout the environment in agriculture and land management, EDCs are encountered every day and contaminate the air, water, soil, and food. Endocrine disruptors function by: (i) Mimicking the action of a naturally-produced hormone, such as estrogen or testosterone, thereby setting off similar chemical reactions in the body; (ii) Blocking hormone receptors in cells, thereby preventing the action of normal hormones; or (iii) Affecting the synthesis, transport, metabolism and excretion of hormones, thus altering the concentrations of natural hormones. Endocrine disruptors have been linked to <\/span>ADHD<\/span><\/a>, Parkinson\u2019s and Alzheimer\u2019s diseases, metabolic disorders, diabetes, cardiovascular disease, obesity, early puberty, infertility and other reproductive disorders, childhood and adult cancers, and other metabolic disorders. (See more on the Pesticide-Induced Diseases: Endocrine Disruption <\/span>page<\/span><\/a>.)<\/span>\u00a0<\/span><\/p>\n

The <\/span>Endocrine Society<\/span><\/a> says: \u201cThere are nearly 85,000 man-made chemicals in the world, many of which people come into contact with every day. Only about one percent of them have been studied for safety; however, 1,000 or more of these chemicals may be EDCs based on their probable endocrine-interfering properties.\u201d A <\/span>wide body of scientific literature<\/span><\/a> finds that many pesticide active ingredients act as EDCs.<\/span>\u00a0<\/span><\/p>\n

As the current study shares, EDCs: \u201care a group of chemicals that are widely used in industrial production, building materials, cosmetics, pesticides, and insecticides. By altering the production, release, transport, metabolism, and binding of endogenous hormones, EDCs increase the risk of diseases across the human life cycle.\u201d While there are various types of EDCs, the main chemicals assessed in this study include bisphenols (BPs), per- and polyfluoroalkyl substances <\/span>(PFAS), which include pesticides<\/span><\/a>, organophosphate flame retardants (OPFRs), and parabens.<\/span>\u00a0<\/span><\/p>\n

\u201cAt present, only a few studies have investigated the effect of EDC exposure on hyperactivity in preschoolers, and these studies have some limitations,\u201d the researchers note. \u201cFor example, the effect of exposure to single types of EDC on hyperactivity in children is mostly investigated through cross-sectional design, which ignores the dynamic development of ADHD symptoms in children and the co-exposure of EDCs in children\u2019s living environments.\u201d (See <\/span>here<\/span><\/a> and <\/span>here<\/span><\/a>.)<\/span>\u00a0<\/span><\/p>\n

Methodology<\/span><\/b>\u00a0<\/span><\/p>\n

In collaboration with the Wuhu Maternal and Child Health and Family Planning Service Center, the researchers include 823 mother\u2013child pairs from 13 urban and rural kindergartens across three districts and counties in Wuhu City, China. The mothers collected morning urine samples from preschoolers (aged 3\u20136 years old) and completed behavioral surveys. The urine samples were tested for 24 EDCs, including eight bisphenols, six PFAS, five organophosphate flame retardants, and five parabens.<\/span>\u00a0<\/span><\/p>\n

The final analyses included 22 of the 24 EDCS due to low detection rates of bisphenols. The preschoolers\u2019 hyperactive behaviors are evaluated using the hyperactivity index scale in <\/span>Conners\u2019 Parent Rating Scale-Revised<\/span><\/a> (CPRS-48). Data from the biomonitoring samples and surveys were used in statistical analyses to assess associations between hyperactive behavior and both single and mixture exposure to EDCs.<\/span>\u00a0<\/span><\/p>\n

Results<\/span><\/b>\u00a0<\/span><\/p>\n

\u201cWe identified two distinct hyperactivity classes (low and high) in line with <\/span>previous studies<\/span><\/a>,\u201d the authors note. \u201c<\/span>Previous studies<\/span><\/a> have confirmed that children with ADHD show some symptomatic features during the preschool period, and these symptoms can persist for a long time.\u201d<\/span>\u00a0<\/span><\/p>\n

Based on the surveys, the study finds that boys are generally at a higher risk of following a high hyperactivity trajectory compared to girls. The researchers provide a plausible explanation in saying: \u201cThis disparity might be attributed to certain genes located on the Y chromosome, such as those involved in dopamine receptor function, which have been associated with an increased risk of developing <\/span>hyperactive symptoms in males<\/span><\/a>. Moreover, increased testosterone levels in boys may enhance dopamine system activity, contributing to heightened impulsivity and externalizing behaviors. Furthermore, this disparity may also be influenced by factors such as differences in the manifestation of hyperactivity symptoms between boys and girls, as well as diagnostic biases, including clinician-related prejudices and social expectations.\u201d<\/span>\u00a0<\/span><\/p>\n

The mixture exposure modeling from the urine samples, however, reveals gender stratification with significant positive relations to hyperactivity trajectories only in girls. \u201cThe Q-gcomp model found that the EDCs mixture was significantly associated with hyperactivity trajectories in both boys and girls, but the effect was more pronounced in girls,\u201d the authors explain. They continue, \u201cThis may be influenced by sex hormones. EDCs can mimic estrogen, bind to estrogen receptors, interfere with the hypothalamic-pituitary\u2013gonadal axis, and affect normal hormone regulation, which may result in symptoms such as attention deficit and hyperactivity. Furthermore, <\/span>Frederiksen et al.<\/em> (2020)<\/span><\/a> demonstrated that estrogen levels in prepubescent girls are significantly higher than those in boys. Therefore, the effect of exposure to the EDCs mixture may be greater in girls.\u201d<\/span>\u00a0<\/span><\/p>\n

Previous Research<\/span><\/b>\u00a0<\/span><\/p>\n

Similar research, covered in previous <\/span>Daily News<\/span><\/i><\/a>, published in <\/span>Environment International<\/span><\/i><\/a>, <\/span><\/i>finds that young children who exhibit higher levels of pesticide metabolites in their urine show more pronounced neurobehavioral problems at the age of ten. Researchers in China document how exposure during early childhood, especially during the sensitive window before the age of two, is linked to hyperactivity\/inattention problems such as ADHD. While adding to the body of science connecting pesticide exposure to <\/span>learning and developmental disorders<\/span><\/a>, this study offers a \u201cnovel perspective on characterizing the fluctuation in repeated measurements of multiple environmental chemicals and identifying the potential critical windows,\u201d the authors share.\u00a0<\/span>\u00a0<\/span><\/p>\n

Additional scientific literature, cited within the current study, shows:<\/span>\u00a0<\/span><\/p>\n