Exposure To Bisphenol A And Its Relationship With Obesity In School-age Children

Objective1. To learn bisphenol A exposure level, physical development and bisphenol A exposure related habits in school-age children.2. To examine the relationship between urine bisphenol A concentration and children obesity,the relationship between bisphenol A exposure related habits and urine bisphenol A concentration or obesity in school-age children.Methods505 pupils aged 6-11 years were randomly selected from 4 primary schools in Yangpu District and Zhabei District, Shanghai. Spot urine samples were collected and total urine BPA concentrations were measured by high performance liquid chromatography. Their height and weight were measured and recorded, and body mass index(BMI) was calculated. Self-designed questionnaires were collected to know bisphenol A exposure related habits in school-age children.Results1. Urine bisphenol A concentrationsBisphenol A was detected in 77.2% of urine samples. The concentrations ranged from ND- 79.52ng/ml with a median of 1.32ng/ml. Urine bisphenol A detection rate has no significant difference between boys and girls. Urine bisphenol A concentrations were higher in girls than boys before and after corrected by urine creatinine(P<0.001). The detection rate was significantly higher in 10-11 years old than 6-7 years old(P<0.001), 8-9 years old(P<0.05) children; urine bisphenol A concentrations were significantly higher in 10-11 years old than 6-7 years old children(P<0.05). The calculated maximum value of bisphenol A daily intake was 2.43×103ng/kg bw/d and was lower than the TDI in Europe.2. Bisphenol A exposure related habitsCarbonated drinks in summer, carbonated drinks in other seasons, metal canned carbonated drinks, other metal canned food, plastic cups water drinking, hot plastic cups water drinking, bucket water drinking, the consumption of bucket water?500ml, hot bucket water drinking, machine-printed store receipts contact were detected in 64.2%, 40.9%, 16.3%, 25.8%, 54.9%, 22.5%, 34.6%, 20.5%, 16.1%, 42.3% of children completing questionnaires respectively.3. The relationship between bisphenol A exposure related habits and urine bisphenol A concentrationsUrinary bisphenol A concentrations were significantly higher in metal canned food group than no metal canned food group after corrected by urine creatinine(P<0.05). Generalized Linear Model analyses showed that urine bisphenol A concentrations were significantly higher in regularly drinking metal canned carbonated beverage group than regularly drinking plastic bottled carbonated beverage group(P<0.01). Rank correlation analyses showed that urine bisphenol A concentrations were significantly associated with increasing habits scores(rs=0.101, P < 0.05). Generalized Linear Model analyses showed that urine bisphenol A concentrations were significantly associated with increasing habits scores(P<0.05), and relative to those in the lowest habits scores quartile, children in the fourth habits scores quartile had higher urine bisphenol A concentrations(P<0.05)?4. The relationship between bisphenol A exposure and obesityThe overweight/obesity, obesity rates were 32.7%, 12.7% respectively. The obesity rate was significantly higher in boys than girls(P<0.001), while there was no statistical difference among different age groups. The obesity rate was significantly higher in low household income group than high household income group(P<0.01).The difference of urine bisphenol A detection rate and concentrations was not statistically significant among obesity, overweight, underweight and normal weight group. When stratified by sex or age, urine bisphenol A concentrations were lower in obese children than normal weight children of 6-7 years of age(P<0.05).The consumption of bucket water was significantly different between obesity group and normal weight group(P<0.05), and the difference of other bisphenol A exposure related habits distribution was not statistically significant between obesity group and normal weight group. Habits scores difference was not statistically significant between obesity group and normal weight group. Multivariate unconditional logistic regression analysis showed that obesity rate was higher in high bucket water consumption group than low consumption group.Conclusion1. Bisphenol A exposure was widespread among school-age children, and bisphenol A exposure level was higher in girls, older children than boys, younger children respectively. The calculated daily intakes were lower than TDI in Europe.2. School-age children had some bisphenol A exposure related bad habits, and there was no significant difference among different sex/age groups.3. Cans are important sources of bisphenol A exposure, and bad habits may increase the risk of bisphenol A exposure.4. Overweight, obesity were serious among school-age children, and the problem was more serious in boys, low family income group than girls, high family income group respectively.5. The consumption of bucket water may be related to obesity.