Distribution Characteristics Of Phthalates In Towels And Risk Assessment Of Skin Exposure

Phthalate esters（PAEs）are a class of endocrine disruptors widely used in textiles.Towels as an important household textile,may expose people to PAEs via the skin,further leading to health risks.In this study,we first collected unused towel samples and analyzed the contamination characteristics of five PAEs and the relationship between their product characteristics and contamination levels;secondly,we investigated the effects of towel use on the distribution and accumulation of PAEs through towel use experiments and simulated washing experiments;further,we determined the estimated daily intake（EDI）of PAEs in used face and bath towels for adults and children of different age groups and investigated the factors affecting the EDI;finally,we analyzed the health risks of PAEs in adults and children of different age groups after using face and bath towels based on risk index models and receptor effect models.The main findings and conclusions of the study are as follows:（1）The detection frequencies of dimethyl phthalate（DMP）,diethyl phthalate（DEP）,dibutyl phthalate（DBP）,diisobutyl phthalate（Di BP）,and di（2-ethylhexyl）phthalate（DEHP）in the unused towel samples were higher than 60%.The maximum concentration ofΣ₅PAEs was 2510 ng/g,indicating that the unused towels were contaminated with PAEs to a certain extent during the production,processing,and packaging process.DBP（132.5 ng/g）and Di BP（49.07 ng/g）were the major PAEs in unused towels,indicating that DBP and Di BP are still the major plasticizers used in the production and manufacture of towels in the Chinese market.The mean concentrations of DMP,DBP,Di BP,and DEHP were higher in bath towels than in face towels.The mean concentration of Di BP was significantly higher in cotton towels than in non-cotton towels（p<0.05）.The mean concentrations of DMP,DEP,DBP,and Di BP were significantly higher in store-bought towels than in online purchases（p<0.05）.The price and density of towels had less effect on PAEs contamination in towels,and towel dyeing and surface printing increased the level of PAEs contamination in towels.PAEs contamination in towels is widespread,but the level of contamination is low compared to other textiles.（2）The results of scanning electron microscope（SEM）showed differences in surface morphology between unused and used towels.Used towels usually had more dense thread columns and rougher surfaces.Higher levels of DBP,Di BP,and DEHP with longer carbon chains and lower levels of DMP and DEP with shorter carbon chains were found in the used towels by adults and children.The concentration of PAEs in towels made of coral velvet was significantly higher than that of cotton（p<0.05）.The results of simulated washing experiments showed that the median concentrations of DMP,DEP,Di BP,DEHP,andΣ₅PAEs in towels decreased after water washing,but the removal rate of PAEs in towels by water washing mode gradually decreased with the increase of octanol-water partition coefficient(K_OW).The median concentrations of DMP,Di BP,DBP,and DEHP in the towels increased after detergent washing,indicating that high concentrations of PAEs in the detergent may cause secondary contamination of the towels.（3）Based on the concentration of PAEs in the used face and bath towels,the order of EDI values for adults was DEHP>DBP>Di BP>DMP>DEP,while the order of EDI values for children was Di BP>DEHP>DEP>DBP>DMP.The material of the face and bath towels,use duration,and user’s gender were the main factors affecting the dermal exposure dose of PAEs.The EDI values of face and bath towels made of coral velvet were significantly higher than those of cotton（p<0.05）,posing a greater health risk to adults and children.The longer the face and bath towels are used,the more likely they are to pose a potential risk to humans.The potential risk to humans from used face and bath towels was higher for adult women than for men.The hazard quotient（HQ）and hazard index（HI）of the five PAEs in towels for the population are much less than 1,indicating that PAEs had no significant non-carcinogenic health risk.The dermal cancer risk（DCR）value for DEHP was less than 1×10^-6,but long-term exposure may pose a potential carcinogenic risk.We recommended that the population regularly change the face and bath towels they use daily to reduce the potential risk of PAEs to humans.