Search

• Lead intoxication decreased serum TSH level in school- age children. • Lead intoxication increased serum GABA level in school- age girls. • BLL and serum Glu level were negatively correlated with school- aged children's IQ. • The frequency of mother smoking and drinking un-boiled stagnant tap water were risk factors of lead intoxication. • Eating fresh fruits, vegetables and soy products regularly may protect against lead intoxication. Lead exposure is one of the most concerning public health problems worldwide, particularly among children. Yet the impact of chronic lead exposure on the thyroid status and related intelligence quotient performance among school-age children remained elusive. The aim of this study was to evaluate the influence of lead exposure on the thyroid hormones, amino acid neurotransmitters balances, and intelligence quotient (IQ) among school-age children living nearby a lead-zinc mining site. Other factors such as rice lead levels, mothers' smoking behavior, and diet intake were also investigated. A total of 255 children aged 7-12 years old were recruited in this study. Blood lead level (BLL), thyroid hormones including free triiodothyronine (FT3), free thyroxine (FT4) and thyroid stimulating hormone (TSH), and amino acid neurotransmitters such as glutamate (Glu), glutamine (Gln), and γ-aminobutyric acid (GABA) were measured using graphite furnace atomic absorption spectroscopy (GFAAS), chemiluminescence immunoassay, high performance liquid chromatography (HPLC). Raven's standard progressive matrices (SPM) and the questionnaire were used to determine IQ and collect related influence factors. The average BLL of children was 84.8 μg/L. The occurrence of lead intoxication (defined as the BLL ≥ 100 μg/L) was 31.8%. Serum TSH levels and IQ of lead-intoxicated children were significantly lower than those without lead toxicity. The GABA level of girls with the lead intoxication was higher than those with no lead-exposed group. Correlation analyses revealed that BLL were inversely associated with the serum TSH levels (R= -0.186, p < 0.05), but positively related with IQ grades (R = 0.147, p < 0.05). Moreover, BLL and Glu were inversely correlated with IQ. In addition, this study revealed four factors that may contribute to the incidence of lead intoxication among children, including the frequency of mother smoking (OR = 3.587, p < 0.05) and drinking un-boiled stagnant tap water (OR = 3.716, p < 0.05); eating fresh fruits and vegetables (OR = 0.323, p < 0.05) and soy products regularly (OR = 0.181, p < 0.05) may protect against lead intoxication. Lead exposure affects the serum TSH, GABA levels and IQ of school-aged children. Developing good living habits, improving environment, increasing the intake of high-quality protein and fresh vegetable and fruit may improve the condition of lead intoxication. [ABSTRACT FROM AUTHOR]

Perfluorooctane sulfonates (PFOS) are regarded as a category of chemicals with persistence, bioaccumulation, and toxicity. Understanding dynamic flows, stocks, and emissions of PFOS on a macro spatial and temporal scale can help provide a scientific basis for their sound management. In this work, a dynamic material flow analysis (d-MFA) model was built to characterize and analyze the cycles of PFOS in mainland China over the period 1985-2019. Flows, stocks, and environmental emissions were calculated and the sensitivity and uncertainty of the results were then analyzed. Results show that domestic production was the primary source of PFOS in China, most of which was flowed to the domestic market in the form of final products, with the remainder exported to international markets; soil and water were the main sinks of PFOS in China, with emissions from the usage stage contributing the largest portion (103 tons in 2019). The number of inflows and outflows were relatively low before 2000, but gradually increased until 2009 when the relevant convention was issued. Since 2005, in-use stocks and emissions of PFOS have grown yearly. In addition, stocks in landfill have been climbing since 1985. End-of-life management was still dominated by traditional methods, such as landfill and incineration, while there was a trend towards green treatments. This study can provide basic data and theoretical support for the sound management of PFOS in China.

Approximately 1 000 chemicals were screened in surface waters from downstreams of Yellow River and Yangtze River using GC-MS coupled with Automated Identification and Quantification System with a Database (AIQS-DB). 95 pollutants were detected in water samples from Yellow River in Shandong Province and 121 in those from Yangtze River in Jiangsu Province. The pollutants involved n-alkanes, PAHs, phenols, nitro compounds, phthalates esters (PAEs), pesticides and pharmaceuticals, etc. The average concentrations of n-alkanes, 16 priority PAHs and 6 priority PAEs were 1 806 ng/L, 27 ng/L, 77 ng/L in water samples from Yellow River and 720 ng/L, 30 ng/L, 2 166 ng/L in water samples from Yangtze River respectively. Besides, 9 and 11 pesticides were detected in water samples from Yellow River and Yangtze River respectively. The levels of pollutants showed stronger site dependence in samples from Yellow River than those from Yangtze River. Combination of GC-MS and AIQS-DB shows high efficiency in regional pollutants survey.