Parent and Halogenated Polycyclic Aromatic Hydrocarbons in the Serum of Coal-Fired Power Plant Workers: Levels, Sex Differences, Accumulation Trends, and Risks.

Workers in coal-fired power plants are at a high risk of exposure to polycyclic aromatic hydrocarbons (PAHs) and their halogenated derivatives (HPAHs), yet no studies have investigated such exposure of HPAHs. In this study, 12 PAHs and 8 chlorinated PAHs, but no brominated PAHs, were detected in >80% of serum samples from workers of a coal-fired power plant in eastern China. Serum HPAH concentrations were higher in plant workers (16-273 ng/g lipid) than in people without occupational exposure (12-51 ng/g lipid), and serum PAH and HPAH concentrations both in male and female workers were positively correlated with the occupational exposure duration, with an estimated doubling time of 11-17 years. Correlations were found between concentrations of ∑8HPAHs and ∑12PAHs but not between 7-chlorobenz[a]anthracene (7-ClBaA) and 1-chloropyrene (1-ClPyr) and their respective parent PAHs. In males, total concentrations of PAHs and HPAHs were positively correlated with pulmonary hypofunction and hypertension but not with abnormal electrocardiogram. The benzo[a]pyrene equivalents ratio of ∑8HPAHs/∑12PAHs was 0.3 ± 0.1. Among the HPAHs in the serum, 9-chlorophenanthrene, 7-ClBaA, and 1-ClPyr showed high health risks. This study is the first report on HPAH exposure in coal-fired power plant workers and provides new evidence on the health risks of PAHs and HPAHs in humans.

Comparative Analysis of Polycyclic Aromatic Hydrocarbons and Halogenated Polycyclic Aromatic Hydrocarbons in Different Parts of Perilla frutescens (L.) Britt.

Perilla frutescens (L.) Britt., a medicinal herb and edible plant, is very popular among East Asian countries. The perilla leaves, stems and seeds can be used as traditional medicines and foods. Polycyclic aromatic hydrocarbons (PAHs) and halogenated PAHs (HPAHs) are organic pollutants that are widely present in the environment, such as in water, air and soil, and are harmful to humans. In this study, the contents of 16 PAHs and 4 HPAHs in perilla leaves, stems and seeds were determined by gas chromatography tandem mass spectrometry (GC-MS). A total of 12 PAHs were detected in all samples, and no HPAHs were detected. The total contents of PAHs in perilla leaves, stems and seeds varied from 41.93 to 415.60 ng/g, 7.02 to 51.52 ng/g and 15.24 to 180.00 ng/g, respectively. The statistical analyses showed that there were significant differences in the distribution of PAHs in perilla leaves, stems and seeds. On the basis of the toxic equivalent quantity (TEQ) and incremental lifetime cancer risk (ILCR) model, the cancer risks of the intake of perilla leaves, stems and seeds were assessed to be from 3.30 × 10-8 to 2.11 × 10-5, 5.52 × 10-9 to 5.50 × 10-8 and 1.20 × 10-8 to 1.41 × 10-7, respectively. These were lower than 10-4 (the priority risk level of the EPA) and suggested that there may be almost no cancer risk from the intake of these traditional Chinese medicines (TCMs).

Microplastic-water partitioning of two states halogenated PAHs: Solute and sol.

The complex interactions of contaminants with microplastics significantly affect ecological risk assessments. Studies of the sorption behavior of freely dissolved hydrophobic organic contaminants (HOCs) on microplastics are common. However, concentrations of HOCs in the actual aquatic environment sometimes exceed their water solubility. A possible explanation is that a microplastic-sol-water three-phase medium (TPM) is formed in the actual water environment. Both states HOCs (in solute and sol) have the potential to migrate to particles suspended in water. To confirm this view, four kinds of microplastics and eight halogenated polycyclic aromatic hydrocarbons (HPAHs) were selected to examine the partitioning of HPAHs between microplastics and water (sol and solute). Both monolayer and multilayer coverage of HPAHs onto microplastics occurred, and chemical sorption dominated the pseudo-sorption mechanism. The microplastic-water partition ratios of HPAHs (0.12-0.74) were approximately four to five orders of magnitude lower than their corresponding KOW values, suggesting that mechanisms other than sorption were involved. Apparently, the sol HPAHs contributed almost identically large increments to both microplastics and water, and closed the gap. For microplastic-supported HPAHs, the contribution of the sol fraction was more than triple that of the dissolved fraction; the key influencing factor was the water solubility of HPAHs.

Polycyclic aromatic hydrocarbons and their halogenated derivatives in soil from Yellow River Delta: Distribution, source apportionment, and risk assessment.

The distribution of polycyclic aromatic hydrocarbons (PAHs) and halogenated PAHs (HPAHs) in surface soils from the petroleum industrial area of the Yellow River Delta (YRD) in China were investigated. The total concentrations of 16 PAHs ranged from 19.6 to 1560 ng/g, while 22 HPAHs ranged from 2.44 to 14.9 ng/g. Moreover, a high degree of spatial distribution heterogeneity was observed for both PAHs and HPAHs, which is likely attributed to the distinct industrial activities in studied area. The combustion of biomass and petroleum were identified as primary sources of soil PAHs and HPAHs in the YRD. Furthermore, benzo[b]fluoranthene, benzo[k]fluoranthene, and benzo[g,h,i]perylene exhibited high ecological risks (with risk quotients of 1.47, 1.44, and 1.02, respectively) in specific sites within the YRD. Considering the high toxicity of HPAHs and their potential joint environmental effects with PAHs, continuous attention should be directed towards the environmental risks associated with both PAHs and HPAHs.

Parent and halogenated polycyclic aromatic hydrocarbons exposure in aluminum smelter workers: Serum levels, accumulation trends, and association with health indicators.

Polycyclic aromatic hydrocarbons (PAHs) and their halogenated derivatives (HPAHs) can be unintentionally formed and released during industrial thermal processes. However, information on internal exposure and health risks of PAHs and HPAHs for thermal industry workers is very limited. In this study, serum samples from 220 aluminum smelter workers in East China were analyzed, and the relationship between the levels of these pollutants and various health indicators was also assessed. The workers had markedly higher serum concentrations of PAHs and HPAHs than the controls. The serum concentrations of ∑13PAHs and ∑9HPAHs increased with increasing age and occupational exposure duration in male workers. A positive correlation was observed between the ∑13PAH and ∑9HPAH serum concentrations, and the concentration of ∑13PAHs was approximately 50 times higher than that of ∑9HPAHs. For benzo[a]pyrene equivalent (BaPeq)-based risk assessment, the contribution of PAHs and HPAHs to the risk was 80 % and 20 % in the workers. PAHs and HPAHs showed a positive association with pulmonary hypofunction, hypertension and abnormal electrocardiogram. This study indicates occupational exposure to these toxic pollutants remains a significant issue and provides evidence that elevated serum levels of ∑13PAHs and ∑9HPAHs may be associated with an increased risk of lung and cardiovascular diseases.

[Determination of 15 halogenated polycyclic aromatic hydrocarbons in aquatic products by stable isotope dilution coupled with gas chromatography-triple quadrupole mass spectrometry].

Halogenated polycyclic aromatic hydrocarbons (H-PAHs), including chlorinated polycyclic aromatic hydrocarbons (Cl-PAHs) and brominated polycyclic aromatic hydrocarbons (Br-PAHs), are compounds in which one or more hydrogen atoms replaced by chlorine or bromine atoms. These compounds are not only difficult to degrade but also highly fat soluble and toxic. They are a new type of high-risk organic pollutants with structures similar to those of dioxins, and their toxicity is even higher than that of the parent polycyclic aromatic hydrocarbons (PAHs). The bioaccumulation of H-PAHs can be predicted by their octanol-water partition coefficient (Kow); in general, higher bioaccumulation capacity and Kow values indicate greater fat solubility. Therefore, animal-derived foods with higher fat contents, such as animal meat, milk, aquatic products, and their processed forms, are more likely to be contaminated with higher contents of H-PAHs than those with lower fat contents. In this work, a gas chromatography-triple quadrupole mass spectrometry (GC-MS/MS) method coupled with stable isotope dilution was established to determine 15 H-PAHs in aquatic products. The instrument and pretreatment methods were systematically optimized. The GC-MS/MS used in this method can effectively eliminate matrix interferences and features high sensitivity and low analytical cost; thus, it has good application prospects. The samples were added with an isotope internal standard before extraction to calibrate the loss of the tested substance during the pretreatment process, extracted by accelerated solvent extraction, purified using gel permeation chromatography and PRiME HLB columns, and then analyzed by GC-MS/MS. The use of two DB-5MS chromatographic columns (30 m×0.25 mm×0.25 µm) and microplate fluidics technology to connect chromatographic columns 1 and 2 in series led to better separation effects, good peak shapes, and high target compound responses. The 15 H-PAHs demonstrated good linearities in the range of 1-50 µg/L, with correlation coefficients (r) greater than or equal to 0.993. The relative standard deviation (RSD) values of the relative response factor (RRF) of the H-PAHs were less than 9%, the method detection limit (MDL) was 0.009-0.072 µg/kg, and the method quantification limit (MQL) was 0.031-0.240 µg/kg. Three spiked levels of 0.25, 1.0, 2.5 µg/kg were added to the blank samples to determine the recovery and precision. The recoveries for these spiked levels were 74.6%-116.8%, 77.8%-123.2%, and 71.9%-124.8%, respectively, and the corresponding RSDs were 0.6%-8.2%, 0.6%-9.0%, and 0.4%-10.6%, respectively. The total actual content of H-PAHs in aquatic product samples was 0.60-3.54 µg/kg. Among the H-PAHs investigated, 9-chlorophenanthrene (9-ClPhe) showed the greatest detection rate (100%) and highest content (1.15 µg/kg), indicating that H-PAHs widely exist in aquatic products. Thus, further assessment of the dietary exposure risk of these compounds is necessary. The developed method simplifies the pretreatment step, and has the advantages of simplicity, rapid analysis, high recoveries, and good stability. It is suitable for the qualitative and quantitative analysis of H-PAHs in actual aquatic product samples and provides reliable technical support for the residue status and risk assessment of H-PAHs in aquatic products.

[Emission Characteristics and Toxicity Effects of Halogenated Polycyclic Aromatic Hydrocarbons from Coal-Fired and Waste Incineration Power Plants].

Coal-fired power plants (CFPPs) and waste incineration power plants (WIPPs) represent a large portion of polycyclic aromatic hydrocarbons (PAHs) sources in the environment, among which halogenated PAHs (HPAHs) are more toxic to the human body compared with their corresponding parent PAHs. In the current work, we investigated the occurrence, formation mechanism, and toxicity effects of HPAHs in the coal and waste combustion products from three CFPPs and one WIPP. The results indicate that the contents of chlorinated PAHs (Cl-PAHs) in the fly ash from the CFPPs and WIPP were 1.06-1.67 ng·g-1 and 2.76 ng·g-1, respectively, and the contents of brominated PAHs (Br-PAHs) in the fly ash from the CFPPs and WIPP were 26.4-44.2 ng·g-1 and 6.31 ng·g-1, respectively. The HPAH contents in the fly ash from the WIPP were significantly higher than those from the CFPPs primarily due to the abundant plastics in the domestic waste, represented by polyvinyl chloride, resulting in the formation of Cl-PAHs during combustion. The HPAH contents in the fly ash from the pulverized coal-fired (PC) boiler were significantly higher than those from the circulating fluidized bed (CFB) boiler mostly due to the higher combustion temperature operated in the PC boiler. The HPAHs in the fly ash from coal combustion were predominantly 7-BrBaA and 9-ClPhe, and those from domestic combustion were predominantly 9-BrPhe and 2-ClAnt. In addition, the contents of 7-BrBaA and 9,10-Br2 Ant in the coal combustion fly ash were significantly higher than those in domestic waste combustion fly ash, whereas 2-BrFle exhibited a contrasting profile. The content of Br-PAHs in the fly ash treated by semi-dry deacidification was twice that in dust removal fly ash but significantly increased in the chelating agent stabilization fly ash. The Pearson correlation analysis indicated the the formation mechanism of Cl-PAHs and Br-PAHs were the same but a secondary formation of HPAHs during the chelating agent stabilization of the fly ash was deduced. The TEQ values of the HPAHs in the fly ash (8.87×10-3-15.0×10-3 ng·g-1) from the WIPP were similar to those in the fly ash from the CFPPs (10.0×10-3 ng·g-1), which were significantly reduced in the fly ash treated by semi-dry deacidification due to the removal of 7-BrBaA. Moreover, the TEQ values of the HPAHs in the fly ash increased 5.4 times after the chelating agent stabilization. The ecological risk should be considered for the CFPP fly ash due to their massive amount of discharge and high TEQ values.

Emission characteristics of parent and halogenated PAHs in simulated municipal solid waste incineration.

With a self-designed small-scale waste incinerator, emission behaviors of parent and halogenated polycyclic aromatic hydrocarbons (PAHs and HPAHs) were simulated and visualized. According to our results, the 2-3 ring PAHs have higher emission factors (EFs) than those of the 4-6 ring PAHs during waste incineration. The EFs of individual HPAHs are comparable in all incineration products. Overall, the EFs of Æ©16PAH and Æ©3ClPAH decreased in the order of gas > bottom ash > particle > fine particle while the EF order for Æ©6BrPAH is bottom ash > particle > gas > fine particle. Based on qualitative observation, the size distributions of Σ16PAH, Σ3ClPAH, and Σ6BrPAH were characterized by trimodal peaks. Coagulation of fine particles in air may lead to enrichment of target compounds in the coarse particle fraction. The gas-particle partition did not reach theoretical equilibrium and most PAHs and HPAHs were absorbed inside the organic carbon. Estimated mass emission of target compounds in Shenzhen suggests that the gaseous phase from MSW incineration is the major contributor to the urban environment. However, automotive emissions contribute more to urban air pollution than MSW incineration in Shenzhen. Generally, compared with other real waste treatment, waste incineration is a more efficient method for waste-to-energy recovery and produces fewer pollutants, although the resultant carcinogenic substances are never truly harmless.

Size-dependent emission characteristics of airborne parent and halogenated PAHs from municipal solid waste incinerators in Shenzhen, China.

Two waste incinerators were selected for investigation of size-dependent emission characteristics of airborne parent and halogenated PAHs (PAHs and HPAHs) and incidence of these pollutants from trash incineration. The concentrations of total PAHs (gas and particles with aerodynamic diameter 0.43-10 µm) in ambient air of Shenzhen incinerators were at the lower end of the global range while those of HPAHs were higher than those of urban air in other studies. High-ring PAHs dominated in PM2.5 (66%-86%), while low-ring PAHs dominated in PM10 (83%-86%). As for PAHs in gaseous phase, low-ring PAHs were collectively account for 86%-97%. ΣHPAH mainly enriched in coarse particles (>83%). The size distributions of ΣPAH and ΣHPAH were both characterized by bimodal peaks dominate in 9.0-10 µm and subordinate in 4.7-5.8 µm. PAHs and HPAHs enrichment in the coarse particles indicates that particle-bound PAHs and HPAHs from incinerators cannot travel great distances. Model simulation results showed the peak of airborne PAHs and HPAHs occurred in approximate 300 m from incinerator, then their concentrations reduced sharply. The extent of affected areas by municipal solid waste incinerators (MSWIs) seem very large, intensity of impacts can be neglected for the very low level of pollutants. Although waste incineration is perceived as most polluting way to manage waste, our study found the damage from incinerator to be far less than originally feared.