Objectives: To describe the biological results of the political and economic transformations that took place in Poland between 1966 and 2012, based on an analysis of age at menarche, and to determine changes across social groups.Methods: Data were collected in 1966, 1978, 1988, and 2012 in several districts of Poland. The study included 34,940 schoolgirls. Age at menarche was assessed with the use of status quo method. Definition of socioeconomic status was based on 4 factors: urbanization level, mother and father education, and family size.Results: When the political and economic situation in Poland improved, a decrease in age at menarche was observed, whereas in years of crisis it increased. The same social differentiation in menarcheal age observed before the political transformation continued to be present in 2012.Discussion: Socioeconomic changes were significantly associated with age at menarche. Social inequalities, reflected in menarcheal age, continue to be present in Poland.

Background: Environmental pollutions with heavy metals may have toxic effects on human health and development. One of the most detrimental is lead exposure, which may disturb neurodevelopment and linear growth in children. However, data on the effect of lead exposure on nutritional and weight status in children are limited, thus this study aimed to assess the effect of blood lead (Pb) level on nutritional and weight status in preadolescent schoolchildren from the industrialized, mining region in southwestern Poland. Methods: Our study sample involved N = 709 schoolchildren (402 boys and 307 girls) in the preadolescent developmental period (7–11 years of age for boys and 7–10 years of age for girls). Anthropometric measurements were used to assess nutritional and weight status: body mass index (BMI), mid-upper arm circumference (MUAC) and skinfolds thicknesses (triceps, subscapular, abdominal and the sum of skinfolds). Blood Pb level was evaluated and divided into two groups: above (>3.7 μg/dL) and below median value (≤3.7 μg/dL). Results: Analysis of covariance (with children’s age controlled as a covariate) revealed that children with blood Pb level above median value had significantly lower values of BMI, MUAC and all skinfolds (at least p < 0.01). However, this effect was significant only in boys, whereas in girls differences were non-significant (p > 0.05). The highest effect size of blood Pb level was noted for skinfolds thicknesses (partial η²: 0.015 for the sum of skinfolds). Conclusions: Nutritional status in children with higher blood Pb level is significantly impaired in preadolescent boys, who appear to be more sensitive to this environmental factor. Our findings indicate a particular need for nutritional and environmental interventions among preadolescent children in regions with higher lead exposure.