This study aims to assess the relationship between body mass index (BMI) of children and that of their parents in a nationally-representative sample of Iranian population. This cross-sectional nationwide study was conducted in 2011-2012 among 6-18-year-old students and their parents living in 30 provinces of Iran. Socio-demographic information was collected. The BMI values of the children/adolescents were categorized according to the World Health Organization reference curves. Association between parental and student weight status was examined using ordinal regression models after adjustment for potential confounders. Overall, 23043 children and adolescents and one of their parents participated in this study (50.7% boys, 73.4% urban status). Mean age of the subjects was 12.55±3.31 years. Mean BMI values of parents and children/adolescents were 27.0±4.57 and 18.8±4.4 kg/m2, respectively. After adjusting for confounders, overweight and/or obesity in students of both genders was found to be significantly associated with parental overweight and/or obesity. In those students who had obese parents, the odds ratio (OR) of being obese was 2.79 for boys [OR=2.79; 95% confidence interval (CI)=2.44-3.20] and 3.46 for girls (OR=3.46; 95% CI=3.03-3.94) compared to their peers with normal-weight parents. Boys with overweight parents were 1.7 times more overweight than their counterparts with normal-weight parents (OR=1.70; 95% CI=1.15-1.92). Similarly, girls who had overweight parents were more overweight compared to those with normal-weight parents (OR=2.00; 95% CI=1.77-2.25). Our findings highlight the importance of the shared family environment as a multi-factorial contributor to the childhood obesity epidemic and the necessity of implementing family-centered preventive programs.

Concentration, source, and ecological risk of polycyclic aromatic hydrocarbons (PAHs) were investigated in 22 stations from surface sediments in the areas of anthropogenic pollution in the Klang Strait (Malaysia). The total PAH level in the Klang Strait sediment was 994.02±918.1 µg/kg dw. The highest concentration was observed in stations near the coastline and mouth of the Klang River. These locations were dominated by high molecular weight PAHs. The results showed both pyrogenic and petrogenic sources are main sources of PAHs. Further analyses indicated that PAHs primarily originated from pyrogenic sources (coal combustion and vehicular emissions), with significant contribution from petroleum inputs. Regarding ecological risk estimation, only station 13 was moderately polluted, the rest of the stations suffered rare or slight adverse biological effects with PAH exposure in surface sediment, suggesting that PAHs are not considered as contaminants of concern in the Klang Strait.