Evaluating the impact of dermal absorption on internal doses of dechlorane plus in Chinese e-waste recycling employees.

E-waste recycling employees represent a specific population with a high potential for exposure to dechlorane plus (DP). However, the impact of skin-adherent DP on human exposure within this group has not been well characterized. This study aimed to address this gap by collecting handwipe and matched serum samples (n = 86 pairs) of Chinese e-waste recycling employees. In vivo human dermal bioavailability of DP was also examined to achieve effective exposure estimation. As a result, DP was detected in all handwipe and serum samples, indicating the occurrence of widespread exposure in the study population. For all the participants, the median level of ∑DP (the sum of syn-DP and anti-DP) in the serum was 45.1 ng g lipid weight (lw), while handwipe samples showed the loading of 10.8 ng per wipe. Notably, significant associations were found between DP handwipe loadings and matched serum levels (p<0.05). Next, the in vivo human dermal bioavailability was estimated to be 9.54% for ∑DP. Based on this value, the estimated average daily dose was 0.231 ng kg d (median values), contributing 10.9% to serum levels of ∑DP. The significant associations and 10.9% percentage contribution together underscore the non-negligible influence of dermal absorption on DP internal doses in the e-waste recycling employees. Moreover, the extremely high levels of DP (up to 3.64E+04 ng g lw) detected in serum highlight the extent of DP accumulation in humans. Continuous monitoring and assessment are warranted among e-waste workers due to the persistent organic pollutant properties of DP.