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

Characterization and childhood exposure assessment of toxic heavy metals in household dust under true living conditions from 10 China cities

Health hazards caused by metal exposure in household dust are concerning environmental health problems. Exposure to toxic metals in household dust imposes unclear but solid health risks, especially for children. In this multicenter cross-sectional study, a total of 250 household dust samples were collected from ten stratified cities in China (Panjin, Shijiazhuang, Qingdao, Lanzhou, Luoyang, Ningbo, Xi'an, Wuxi, Mianyang, Shenzhen) between April 2018 and March 2019. Questionnaire was conducted to gather information on individuals' living environment and health status in real-life situations. Multivariate logistic regression and principal component analysis were conducted to identify risk factors and determine the sources of metals in household dust. The median concentration of five metals in household dust from 10 cities ranged from 0.03 to 73.18 μg/g. Among the five heavy metals, only chromium in household dust of Mianyang was observed significantly both higher in the cold season and from the downwind households. Mercury, cadmium, and chromium were higher in the third-tier cities, with levels of 0.08, 0.30 and 97.28 μg/g, respectively. There were two sources with a contribution rate of 38.3 % and 25.8 %, respectively. Potential risk factors for increased metal concentration include long residence time, close to the motorway, decoration within five years, and purchase of new furniture within one year. Under both moderate and high exposure scenarios, chromium showed the highest level of exposure with 6.77 × 10-4 and 2.28 × 10-3 mg·kg-1·d-1, and arsenic imposed the highest lifetime carcinogenic risk at 1.67 × 10-4 and 3.17 × 10-4, respectively. The finding highlighted the priority to minimize childhood exposure of arsenic from household dust.

Organic toxicants and emerging contaminants in hospital interiors before and during the SARS-CoV2 pandemic: alkanes and PAHs

Indoor pollution and deposition dust (DD), in particular, are acquiring concern, due to long exposure time and importance of intake by humans through contact and ingestion. Hospitals look a special category of sites, owing to peculiar contaminants affecting them and to presence of people prone to adverse effects induced by toxicants. Four in-field campaigns aimed at understanding the chemical composition of DD were performed in five Italian hospitals. Measurements were performed before (autumn 2019), during (spring 2021), and after (winter 2022) the peak of SARS-CoV2 and when restrictions caused by pandemic were revoked (winter 2023). Parallel measurements were made outdoors (2022), as well as in a university and a dwelling. Targeted contaminants were n-alkanes and polycyclic aromatic hydrocarbons (PAHs), while iso- and anteiso-alkanes were analyzed to assess the impact of tobacco smoking. Total n-alkanes ranged from 3.9 ± 2.3 to 20.5 ± 4.2 mg/g, with higher percentages of short chain homologs in 2019. PAHs ranged from 0.24 ± 0.22 to 0.83 ± 0.50 mg/g, with light congeners (≤ 228 a.m.u.) always exceeding the heavy ones (≥ 252 a.m.u.). According to carbon preference indexes, alkanes originated overall from anthropogenic sources. Microorganisms resulted to affect a hospital, and tobacco smoke accounted for ~ 4-20‰ of DD mass. As for PAH sources, the diagnostic concentration ratios suggested the concourse of biological matter burning and vehicle emission. Benzo[a]pyrene equivalent carcinogenic and mutagenic potencies of depositions at hospitals ranged ~ 9-39 μg/g and ~ 15-76 μg/g, respectively, which seems of concern for health. DD composition in hospitals was different from that outside the premises, as well as that found at university and at dwelling.

Ecological and health risk assessments of polycyclic aromatic hydrocarbons (PAHs) in soils around a petroleum refining plant in China: A quantitative method based on the improved hybrid model

Polycyclic aromatic hydrocarbons (PAHs) are extensively released into the environment by petroleum refining activities, predominantly affecting soil as a major reservoir. This study focuses on an active petroleum refinery in central China and employs a multi-faceted approach, combining geo-statistics, the absolute principal component-multiple linear regression model, and the Monte Carlo simulation, to comprehensively unravel the sources and risks associated with 12 PAHs. The analysis reveals a wide range of PAH concentrations, spanning from 60.23 to 1678.00 μg·kg-1, with an average of 278.91 μg·kg-1. Strikingly elevated PAH levels are primarily concentrated in construction and transportation lands, whereas woodland and grasslands exhibit lower PAH concentrations. In terms of ecological impact, the risk arising from oil-coal combustion significantly surpasses that linked to biomass combustion. meticulous assessments indicate negligible carcinogenic risks for both children and adults within the study area. An innovative hybrid model, which seamlessly integrates risk assessments with source identification, emerges as a pivotal advancement. This hybrid model not only quantifies PAH emission levels from refining activities but also effectively quantifies potential risks from distinct sources. Consequently, this study furnishes a robust theoretical foundation for strategizing PAH pollution risk mitigation. In essence, our research not only contributes a comprehensive understanding of PAH distribution around an active petroleum refinery but also introduces an advanced hybrid model, culminating in valuable insights for devising measures to curtail PAH-related environmental risks.

Spatiotemporal variability of PAHs and their derivatives in sediments of the Laizhou Bay in the eastern China: Occurrence, source, and ecological risk assessment

To understand the pollution status and risk levels in the Laizhou Bay, the spatiotemporal distribution, source, and ecological risk of 16 polycyclic aromatic hydrocarbons (PAHs) and 20 substituted PAHs (SPAHs) were studied in surface sediments in 2022. The findings indicated significant seasonal differences in the concentrations of PAHs and SPAHs under the influences of precipitation, temperature, light, and human activities, with higher storage levels in summer than in spring, and there was also a spatial distribution trend of estuary > coast > offshore. 2-Nitrofluorene (2-NF) and 2-methylnaphthalene (2-MN) were the most abundant components of SPAHs in both spring and summer, with levels of 21.44 ng/g and 17.89 ng/g in spring, 43.22 ng/g and 25.51 ng/g in summer, respectively. The results of the diagnostic ratio and principal component analysis - multiple linear regression identified sources of PAHs and SPAHs as combustion sources, including petroleum, coal, and biomass. The risk level of PAHs was low-to-moderate according to the toxicity equivalent quotient (TEQ) and risk quotient. A novel calculation method based on TEQ was proposed to assess the ecological risk of SPAHs, and the results indicated that the risk level of SPAHs was moderate-to-high.

Anthropogenic impact on soils of protected areas-example of PAHs

The following study presents the concentrations of 10 individual polycyclic aromatic hydrocarbons (PAHs₁₀) and the total concentration of PAHs (ΣPAHs) determined in soils of protected areas in Southern Poland (EU). The protected areas discussed here include 5 landscape parks and 5 nature reserves located in the Małopolska region. Surface soil samples were collected at 39 locations characterised by different natural conditions and different human pressure level. The samples were used to determine the contents of anthracene, benzo[a]pyrene, benz[a]anthracene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[g,h,i]perylene, chrysene, dibenz[a,h]anthracene, indeno[1,2,3-cd]pyrene and naphthalene. These concentrations of individual PAHs ranged from < 0.005 to 6.34 mg/kg. When considering the legal regulations currently in force, this meant that permissible values were exceeded in 23% of the samples analysed, while increased concentrations were found in another 26% of the samples. The limit values were exceeded most in the case of benzo[b]fluoranthene and benzo[a]pyrene. This occurred with samples collected in the vicinity of transportation routes, mainly local roads. In the case of naphthalene and anthracene, the limit values were not exceeded. Increased or excessive PAHs concentrations do not occur in the vicinity of major industrial plants located near the boundaries of individual landscape parks, which indicates how these pollutants spread. The paper also points to the need to develop new legal solutions to improve the method for assessing PAHs concentrations and their impact on valuable natural areas.