Exposure before birth to persistent organic pollutants (POPs) (organochlorine pesticides, industrial chemicals, etc.) may increase the risk of metabolic disorders in adolescence, such as obesity and high blood pressure. This was the main conclusion of a study by the Barcelona Institute of Global Health (ISGlobal), a research center supported by the “la Caixa” Foundation. The study was based on data from nearly 400 children living in Menorca, who were followed from before birth to 18 years.
POPs are toxic, degradation-resistant chemicals that persist in the environment. Examples of these compounds are organochlorine pesticides and insecticides (DDT, etc.). POPs have adverse effects on both human health and the environment and their use is regulated worldwide.
Prenatal exposure to these substances has been associated with cardiometabolic risk factors in childhood, but previously there were no studies evaluating whether these associations continue until adolescence, a developmental stage characterized by significant changes in the endocrine system. and rapid increases in body mass.
The aim of this research, carried out within the framework of the INMA-Environment and Childhood Project, was to study the associations between prenatal exposure to POP and body mass index (BMI), as well as other cardiovascular risk markers. in adolescence. The data of 379 children in Menorca were analyzed. POP levels were measured in umbilical cord blood samples and children were seen periodically between 4 and 18 years of age. At these visits, BMI, body fat percentage, and blood pressure were recorded as they grew. When the child reached the age of 14, the scientists measured blood biomarkers of cardiometabolic risk (cholesterol, triglycerides, glucose, etc.).
The results of this study, published in the journal International Environment, suggest an association between prenatal POP exposure and higher BMI in adolescence, particularly in the case of the fungicide hexachlorobenzene (HCB) and the insecticide compound dichloro-diphenyl-trichloroethane (DDT).
Exposure to these two organochlorines (HCB and DDT¬) was also associated with higher blood pressure in childhood and adolescence and an increased cardiometabolic risk at 14 years of age.
ISGlobal researcher Núria Güil-Oumrait, the first author of the study, explains that “this is the first longitudinal study that analyzes the relationship between persistent organic pollutants and cardiometabolic risk throughout childhood and adolescence Our findings show that the association between these substances and infant BMI persists into adolescence and that prenatal exposures are associated with major risk factors for metabolic syndrome in adults, a condition that today affects one in four people worldwide.
Regarding the mechanisms that could explain this association, Güil-Oumrait points out that “it is believed that POPs can interact with hormone receptors or the generation of free radicals, and the main problem is that these pollutants accumulate in the fatty tissues of living organisms. , where they can persist for years, even decades “.
Martine Vrijheid, coordinator of the study and head of the ISGlobal Childhood and Environment Program, highlights the fact that “some of these substances could be considered endocrine disruptors, ie chemicals that interfere with hormonal regulation. ”. In his view, “more studies are needed in this field, especially focused on childhood and adolescence, which are critical stages of development characterized by a particular vulnerability.”
Barcelona Institute of Global Health (ISGlobal)
Güil-Oumrait, N., et al. (2021) Prenatal exposure to persistent organic pollutants and markers of obesity and cardiometabolic risk in Spanish adolescents. International Environment. doi.org/10.1016/j.envint.2021.106469.