广州市细颗粒物(PM_(2.5))中塑料添加剂的污染特征、影响因素及健康风险评估

PM_(2.5)-bound Plastic Additives in Guangzhou,China:Occurrence,Influencing Factors and Risk Assessment

抗氧化剂是塑料产品中常见的一类添加剂,其在城市大气颗粒物中的污染以及影响因素目前仍缺乏认识。该文以广州市为研究区域,评估细颗粒物(PM_(2.5))中以抗氧化剂为主的常见塑料添加剂的污染状况。结果表明,PM_(2.5)中的抗氧化剂仅以其氧化产物和降解产物的形式存在,总浓度为0.64~19.3 ng/m^(3),较高浓度主要出现在化工和塑料生产企业较为密集的区域。污水处理厂对周边大气中部分抗氧化剂的降解产物也具有显著贡献。气象条件对颗粒物中污染物浓度的影响与污染物的理化性质有关,其中,太阳辐射的影响最为显著,可促进半衰期较长的污染物在颗粒物中的富集。化工和塑料生产企业周边的居民通过呼吸暴露塑料添加剂的剂量高于其他采样点。广州十溴联苯醚的致癌风险远低于风险阈值,也普遍低于我国其他城市的整体风险水平。

Antioxidants are one of the commonly used additives in plastic products.However,their occurrence and behaviors in air are poorly understood.This research revealed the contamination of a number of plastic additives,including antioxidants,brominated flame retardants,and bisphenol A,in PM_(2.5)in Guangzhou,China.As for the antioxidants,only their oxidation and degradation products were found in the PM_(2.5),possibly due to the short atmospheric life of the antioxidants,with total concentrations ranged from 0.64 to 19.3 ng/m^(3).Higher concentrations were found at sites with intensive chemical and plastic manufacturing.Municipal wastewater treatment plant also has a significant contribution to the degradation products of antioxidants in the air.The correlations between concentrations of plastic additives and meteorological factors are largely determined by the physicochemical properties of the pollutants.Surface solar radiation has the greatest effect on the pollutant levels in the particles,which can promote the enrichment of plastic additives with long halflives.The lifetime average daily dose of inhalation exposure to the plastic additives was relatively higher for the residents living around the chemical and plastic manufacturing.The incremental lifetime cancer risk of inhalation exposure to decabromodiphenyl ether in Guangzhou is under the acceptable risk level(10^(-4))and lower than that in other cities of China.