Assessment of PAH exposure and health risks among South Korean firefighters based on urinary PAH metabolites.

Polycyclic aromatic hydrocarbons (PAHs) comprise a group of compounds resulting from the incomplete combustion of organic matter. Firefighters engaged in fire suppression are highly exposed to PAHs. This study centered on evaluating the exposure levels and health risks of PAHs in South Korean firefighters involved in firefighting activities. The concentrations of 10 PAH metabolites in the urine of firefighters were measured immediately after, and two weeks post their engagement in extinguishing a large tire factory fire. The levels of OH-PAHs in urine samples immediately after fire suppression were elevated by a factor of 1.01-1.84 compared to urine samples from non-exposed period. The median concentration of total PAH metabolites (OH-PAHs) was higher in urine samples immediately after fire suppression (5910 ng/g creatinine) than in urine samples from non-exposed periods (5020 ng/g creatinine). However, the ∑OH-PAH levels in firefighters' urine were related to personal habits such as smoking. The concentrations of all individual OH-PAHs in the urine samples of nonsmokers exhibited a substantial increase, ranging from 1.37 to 2.3 times, clearly demonstrating that firefighting activities were a substantial source of PAH exposure. The calculated values associated with the health risks stemming from exposure to PAHs, including carcinogenic risk, total estimated daily intake (TEDI), and hazard quotients/index (HQs/HI), all fell within acceptable limits, indicating negligible risk. However, the HQ/HI values and TEDI for individual and total PAH exposures, except those for naphthalene, were 1.36-2.00 times higher in firefighters' samples taken after firefighting operations compared to those during regular duty. This underscores the need for more comprehensive investigations to comprehend the singular impact of firefighting activities due to the diverse sources of PAH emissions in the environment.

Occurrences, Potential Sources and Health Impacts of Organochlorine Pesticides in Soil from Wuhan, Central China.

This study was designed to determine the occurrence, potential sources, human and ecological risks of organochlorine pesticides (OCPs) in soil from Wuhan, central China. The soil samples were collected from twenty-six sites at soil depth of 1-20 cm from three land-use types and analyzed for the presence of eight OCPs. The instrumental analysis was carried out using Gas Chromatography-Electron Capture Detector (GC-ECD). The obtained result ranged from 0.193 to 135.277 ng g-1 with the mean value of 17.337 ng g-1 for ΣHCHs and 2.479 to 987.248 ng g-1 with the mean value of 80.056 ng g-1 for ΣDDTs. The total sum (ΣOCPs) ranged from 5.44 to 994.44 ng g-1 with the mean value of 97.39 ng g-1. p, p'- DDE was the highest OCP (976 ng g-1) detected in the soil followed by p, p'-DDD (287.454 ng g-1). Pearson correlation analysis indicated that there was a significant correlation between individual OCPs, while a weak and negative correlation between OCPs and selected soil properties. Isomeric ratio results indicated that DDTs in the soil came from historical (early use of DDTs) and HCHs originated from the use of lindane. Incremental lifetime cancer risks (ILCR) indicated that HCHs can cause very low risk for adults while, low risks for children and DDTs can cause low risk on adults and high risks on children.

Organohalogenated Contaminants (OHCs) in Surface Sediments and Water of East Dongting Lake and Hong Lake, China.

East Dongting Lake and Hong Lake are two typical lakes in the middle watershed of the Yangtze River, China. The differences in the hydrological condition and human activities of the region may result in the differences in concentrations, distribution, and sources of contaminants. The levels, sources, distribution, and ecological risk of OHCs, including 15 OCPs, 7 PCBs, and 7 PBDEs in surface sediments and water from this region, were investigated. OCPs and PCBs were the predominant pollutants in water and sediments samples, respectively. Source analysis showed that HCHs, PBDEs, and PCBs were mainly from the historical input of commercial products, but there were recent discharges of DDT into the water. The spatial distribution of OHCs showed that higher levels of OHCs in sediments and water were found in the sampling sites far away from the estuary of Hong Lake, but such obvious distribution characteristic was not found in East Dongting Lake. TOC played a crucial role in the retention of OCPs in the sediments of Hong Lake, but significant correlation between TOC and OCPs for East Dongting Lake, TOC and PCBs or PBDEs for both lakes were not found. The possible adverse biological effects could be caused by OCPs residues in sediments of both lakes, and it was worse for Hong Lake. The noncarcinogenic and carcinogenic risk assessment of HCHs and DDTs indicated the water quality of both lakes was safe for bathing and drinking. The potential ecotoxicological risks of PBDEs and PCBs of both lakes were rather low.

Determination of Heavy Metal Concentrations and Their Potential Sources in Selected Plants: Xanthium strumarium L. (Asteraceae), Ficus exasperata Vahl (Moraceae), Persicaria attenuata (R.Br) Sojak (Polygonaceae), and Kanahia laniflora (Forssk.) R.Br. (Asclepiadaceae) from Awash River Basin, Ethiopia.

The objective of this study was to determine the concentrations, potential sources and evaluate the risks of heavy metals in selected plants from Awash River Basin, Ethiopia. A total of 57 samples were analyzed from four different plant species. Microwave-assisted digestion was applied to digest the samples and the concentration of nine elements namely: Al, Cr, Ni, Cu, Zn, As, Cd, Hg, and Pb were analyzed using Inductively Coupled Plasma-Mass Spectrometry (ICP- MS) (Thermos X SERIES2). The obtained data were analyzed using Statistical Package for Social Sciences (SPSS IBM version 20). The recorded mean concentration of heavy metals in the plants were 1.934, 0.023, 0.023, 0.045, 0.129, ND, 0.025, ND, and 0.009 mg/kg in Xanthium strumarium L.(Asteraceae); 0.834, 0.036, 0.024, 0.021, 0.090, ND, 0.002, 0.001, and 0.006 mg/kg in Ficus exasperata Vahl (Moraceae); 1.603, 0.018, 0.019, 0.025, 0.133, 0.005, 0.006, 0.002, and 0.012 mg/kg in Persicaria attenuata (R.Br) Sojak (Polygonaceae); and 0.557, 0.010, 0.010, 0.024, 0.098, ND, 0.012, 0.020, and 0.004 mg/kg in Kanahia laniflora (Forssk.) R.Br. (Asclepiadaceae) for Al, Cr, Ni, Cu, Zn, As, Cd, Hg, and Pb, respectively. Pearson's correlation analysis indicated that there was a strong positive correlation between Al-Ni (r = 0.927**) and Zn-Cu (r = 0.764**) at α = 0.01 significant level. Principal component analysis (PCA) indicated that the sources of heavy metals in the plants were associated with anthropogenic factors. The mean concentrations of all elements except Cd in Xanthium strumarium L. (Asteraceae) and Pb in Ficus exasperata Vahl (Moraceae) were below the permissible limit of FAO/WHO (2001 /2005).

Concentrations, Distribution, Sources and Ecological Risk Assessment of Trace Elements in Soils from Wuhan, Central China.

This study aimed to determine the concentration levels, potential sources and ecological risks of eleven trace elements, namely Cr, Fe, Co, Ni, Cu, As, Sb, Cd, Zn, Hg and Pb, in the soil from Huangpi district, Wuhan, Central China. Soil samples were collected from eighteen sites at soil depths of 1⁻10 and 10⁻20 cm and analyzed using Inductively Coupled Plasma-Mass Spectrometer ICP-MS (Thermo X SERIES 2, Scientific and Innovative Technology Co. Ltd., Beijing, China). The recorded mean concentration of the elements were in a decreasing order of Fe > Co > Cr > Ni > Pb > Cu > As > Cd > Sb > Zn > Hg. The mean concentration of trace elements, soil pH and total organic carbon (TOC) were higher at a soil depth of 1⁻10 cm. The obtained mean concentration of Cr, Co, As, Cd, Ni, Cu, Hg and Pb were above the soil background values of Wuhan and Hubei Province. The mean concentration values of Co, Ni and Cd, exceeded the recommended FAO (Food and Agriculture Organization)/ISRIC (International Soil Reference and Information Centre) (2004) and WHO/FAO (2001) values. Pearson's correlation analysis illustrated that there was a strong and significant correlation between trace elements, whereas, a weak positive and negative correlation between elements and soil properties (pH and TOC). The principal component analysis (PCA) and cluster analysis (CA) result indicated that the concentration of trace elements in Huangpi soil were originated from anthropogenic sources. Potential ecological risk index (RI) of this study revealed that there is a high ecological risk of trace elements in the soil. Enrichment factor (EF) and geo-accumulation index (Igeo) of trace elements for this study indicated that the study area is strongly contaminated with Cd and Co. Generally, the finding of this research showed that Huangpi soil is contaminated.