Characterization and distribution of brominated flame retardants in soils from informal E-waste recycling facilities: insights from Pakistan

Abstract

E-waste, a global environmental concern, particularly affects developing nations due to the rise in informal recycling practices. This leads to contamination of environmental matrices, posing threats to both ecosystems and human health. To assess this issue, we monitored brominated flame retardants (BFRs) in 164 samples (soil) from 32 informal e-waste operational locations and 9 background locations across nine mega cities of Pakistan from September 2020 to December 2021. The mean concentrations (ng/g) of & sum;27PBDEs (polybrominated diphenyl ethers), & sum;2PBB (polybrominated biphenyls), HBB (hexabromobiphenyl), and & sum;HBCDD (hexabromocyclododecane) were 176 ( 0.76-11141), 31.0 (0.65-58.0), 1.39 (0.01-42.8), and 12.0 (0.22-461), respectively. These levels were significantly higher (6 to tenfold) than those at background sites. Karachi, Faisalabad, Gujranwala, and Lahore exhibited high levels of all BFRs. Notably, BDE-209 (mean = 45.5 ng/g) ranged (0.13-1152 ng/g) exhibited higher level in soil samples. Seasonally, total Sigma BFR concentrations (ng/g) ranked higher in winter (11,620), followed by spring (3874), autumn (3139), and summer (1207) indicating a seasonal impact of recycling activities. The average daily dose for soil ingestion (ng/kg/day) was estimated for BDE-209 (0.10973) in Faisalabad, followed by BDE-47 (0.08616) and BDE-99 (0.06788) in Karachi. Our findings showed that these values were lower than RfD values, suggesting no ingestion risk from studied BFRs. However, the growing prevalence of such informal e-waste recycling facilities could lead to increased exposure to toxic chemicals in near future.