Pollution Characteristics And Human Exposure Assessment Of Organic Corrosion Inhibitors And Ultraviolet Absorbents In Dust From An E-waste Dismantling Area In South China

Benzotriazole(BTR),benzothiazole(BTH),benzotriazole ultraviolet stabilizer(BUV),benzophenone(BP),as well as their derivatives are emerging contaminants that are produced at high volumes and are widely used as corrosion inhibitors,vulcanization accelerators and ultraviolet absorbents in electronic and electrical products(e-products).However,there is a knowledge gap about the occurrence of and human exposure to these compounds in e-waste dismantling areas.In the present study,6 BTRs,9 BTHs,9 BUVs and 5 BPs were analyzed in indoor dust samples collected from representative e-waste dismantling workshops and adjacent residential houses,as well as from control urban residential houses.The present study attempted(1)to reveal the current pollution status,including the occurrence,concentrations,and composition profiles of BTRs,BTHs,BUVs and BPs in indoor dust from an e-waste dismantling area;(2)to provide a comparative analysis of human exposure to these emerging compounds via dust ingestion and dermal absorption between the heavily polluted and the general indoor environments.The main results were as follows:The concentrations of BTRs and BTHs in e-waste dismantling workshop dust were 509-43100 and 590-4430 ng/g,respectively,which were significantly higher than those in local residential house dust(26.7-1330 and 268-3350 ng/g)and control urban house dust(70.5-1280 and 400-3650 ng/g).The result indicates that e-waste dismantling activities contribute to considerable residues of BTRs and BTHs in indoor dust.BTR,BTH and 2-hydroxy-benzothiazole(2-OH-BTH)were identified as the predominant compounds across three types of dust samples,cumulatively representing over 80% of ?BTs(the sum of ?BTRs and ?BTHs).The different applications of BTRs and BTHs in e-products were clarified based on correlations analysis.Similar to BTRs and BTHs,significantly higher concentration of BUVs were also found in indoor dust from e-waste workshops(median: 1790 ng/g,range:314-13100 ng/g)compared to local residential houses(194,58.3-701 ng/g)and control urban residential houses(790,247-8190 ng/g),indicating that e-waste dismantling activities also lead to high residues of BUVs in indoor dust.However,the concentration of BPs in control urban residential house dust(median: 203 ng/g,range: 43.4-751 ng/g)was higher than that in e-waste workshop dust(141,28.4-1460 ng/g)and local residential house dust(63.8,16.2-296 ng/g),suggesting that BP-containing consumables such as sunscreens and cosmetics are broadly and largely applied in urban residential houses.The influence of BTRs,BTHs,BUVs and BPs contaminations on the local household environment by dust diffusion and transport from surrounding e-waste dismantling workshops may be lower because of the relatively low volatility of most of them.The estimated daily intakes(EDIs)of BTRs,BTHs,BUVs and BPs through dust ingestion and dermal absorption for occupational workers were much higher than those for local and urban residents,implying that a potentially high risk can be posed to occupational workers.To the best of our knowledge,this is the first study to report the widespread occurrence of BTRs,BTHs,BUVs and BPs in e-waste dismantling area.