Levels, distribution, sources and children health risk of PAHs in residential dust: A multi-city study in China br

Background: Polycyclic aromatic hydrocarbons (PAHs) are typical residential pollutants mainly from biofuel combus-tion that impose inevitable risk to children. The PAHs in residential dust is universal in most Chinese households withan obvious public health concern.Methods: In this observational study, a total of 235 residential dust samples from 8 Chinese cities (Panjin, Shijiazhuang,Lanzhou, Luoyang, Xi'an, Wuxi, Mianyang, and Shenzhen) were collected from April 2018 to March 2019, which wereextracted and analyzed for 16 priority PAHs by HPLC/FD-UV. Diagnostic ratios, hierarchical clustering analysis andprincipal component analysis were applied simultaneously for source apportionments. Incremental lifetime cancerrisk was employed to estimate children's health risks based on the assumed exposure scenarios. Spearman correlation,Mann-WhitneyUtest, Kruskal-WallisHtest and Partial Least Squares were used to screen the factors affecting the con-centration of PAHs in residential dust.Results:The median concentration of n-ary sumation 16PAHs in residential dust from 8 cities was 44.11 mu g/g (0.04 - 355.79 mu g/g). n-ary sumation 16PAHs were found both higher in dust samples in heating season and from downwind households only in Mianyang(p<0.05). The leading two sources of PAHs were combustion processes and automobile exhaust emissions based onfour principal components that accounted for 74.29 % of the total variance. Indoor air environmental factors, house-hold characteristics, and residents' behavioral lifestyles may be the influencing factors of residential dust PAHs. Thecarcinogenic risk of children aged 0 - 5 years, under the moderate exposure level of PAHs in residential dust, exceededthe acceptable level (10-5-10-4for dermal contact and 10-6-10-5for ingestion)Conclusions: There was serious PAHs pollution in residential dust under actual living conditions in eight cities acrossChina. More evidence-based measures were needed to control PAHs pollution to safeguard children's health accordingto appointed sources and influencing factors in residential dus

Automated summary

Serious PAHs pollution was found in residential dust in eight cities across China, mainly from biofuel combustion. The concentrations of PAHs in residential dust exceeded acceptable levels, and the combustion processes and automobile exhaust emissions were identified as the main sources. Indoor air environmental factors, household characteristics, and residents' behavioral lifestyles may affect the concentration of PAHs in residential dust.