Levels of neonicotinoid pesticides exposure and their influencing factors in 7-year-old children from Laizhou Wan Birth Cohort in Shandong, China

Background Neonicotinoid pesticides (NEOs) are widely used in agriculture and households. Previous studies have shown that populations in the Shandong region are generally exposed to NEOs, with higher environmental NEOs concentrations in Laizhou Wan due to its agricultural activities and geographical characteristics. School-aged children are vulnerable due to high food intake per body weight, warranting further investigation of their NEOs exposure in this area.

Objective To assess the levels of NEOs exposure in 7-year-old children in the Laizhou Wan area of Shandong and to investigate dietary and sociodemographic factors that may influence their NEOs exposure levels.

Methods Based on the Shandong Laizhou Wan Brith Cohort established from 2010 to 2013, this study included 388 children age (7.44±0.67) years who participated in the 7-year follow-up. The concentrations of seven NEOs acetamiprid (ACE), imidacloprid (IMI), clothianidin (CLO), thiamethoxam (THM), thiacloprid (THD), dinotefuran (DIN), and nitenpyram (NIT) in urine were measured using high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Basic demographic information, dietary frequency, and preparation methods of fruits and vegetables were collected through questionnaires. Univariate linear regression was used to examine the associations between urinary NEOs concentrations and demographic information, dietary frequency, and preparation methods of fruits and vegetables. All β values were transformed using a formula (2^β−1)*100 to describe the percentage change (%) in urinary NEOs concentrations for each factor.

Results Among the 7-year-old children, the highest median creatinine-adjusted urinary concentration was for CLO (0.497 μg·g⁻¹), followed by IMI (0.461 μg·g⁻¹). The concentrations for DIN, THM, NIT, THD, and ACE were 0.193, 0.075, 0.013, 0.011, and 0.007 μg·g⁻¹, respectively. The detection rates of six NEOs were above 75%, with IMI having the highest detection rate (99.74%), followed by CLO (98.71%). The univariate linear regression analysis indicated that the frequency of peeling fruits and vegetables before consumption and gender were significantly associated with urinary NEOs concentrations (P<0.05). Compared with children who peeled fruits and vegetables <1 time (per 10 times, the same hereinafter), those who peeled >3 times had 28.99% and 18.83% lower THM and ∑₆NEOs concentrations, respectively. Compared to boys, girls had 23.20%–43.10% higher concentrations of ACE, IMI, THD, DIN, and ∑₆NEOs. The gender-stratified analysis of dietary factors revealed that in boys, those consuming meat and eggs ≥4 times/week had 27.40% and 25.72% lower DIN and ∑₆NEOs concentrations, respectively, compared to those consuming <4 times/week. Boys consuming aquatic products ≥2 times/week had 65.63% higher urinary CLO concentrations compared to those consuming <2 times/week. Compared with boys who peeled fruits and vegetables <1 times, those peeling 1–3 times had 35.11% and 22.46% lower THM and THD concentrations, and those peeling >3 times had 35.43% lower THM concentrations. These results were statistically significant (P<0.05). However, no similar associations were observed in girls.

Conclusion NEOs exposure is common among the 7-year-old children in Laizhou Wan, Shandong. The frequency of peeling fruits and vegetables before consumption and gender may be influencing factors for urinary NEOs concentrations. However, further research and validation in other populations are required to confirm these findings.