Total Polycyclic Aromatic Hydrocarbons Research Articles

Contamination and Health Risk Assessment of Polycyclic Aromatic Hydrocarbons in Seasoning Flour Products in Hunan, China.

Polycyclic aromatic hydrocarbons (PAHs) are persistent organic pollutants with carcinogenic, teratogenic, and mutagenic effects. Dietary intake is one of the significant exposure pathways of PAHs. In this study, gas chromatography-triple quadrupole mass spectrometry (GC-MS/MS) was used to detect 16 priority PAHs listed by the United States Environmental Protection Agency (USEPA) in seasoning flour products distributed in Hunan Province. The consumption of seasoning flour products by the Hunan population was investigated by questionnaire. The results showed that the detection rate of PAHs in seasoning flour products in Hunan Province was 92.41%. Among them, benzo[a]anthracene (BaA), phenanthrene (PHE), fluoranthene (FLA), and chrysene (CHR) were dominant. The total PAHs and benzo[a]pyrene (BaP) contents of soggy seasoning flour product samples were higher than those of crisp samples and chewy samples. The total amount of PAHs in rod-shaped and flaky samples were higher than that in filamentous and granular samples. The margin of exposure (MOE) values of various seasoning flour products and all age groups (children, adolescents, and adults) was much more significant than 10,000. Moreover, the incremental lifetime of cancer risk (ILCR) values of all age groups were below 1 × 10-5. The above results indicate that PAHs in seasoning flour products have a relatively low health risk for the Hunan population. Still, it is recommended that susceptible populations (children, adolescents, etc.) should control their intake of flour products.

Associations of dietary factors and xenobiotic intake with faecal microbiota composition according to the presence of intestinal mucosa damage.

Diet is a major modulator of gut microbiota, which plays a key role in the health status, including colorectal cancer (CRC) development. Several studies and meta-analyses have evidenced an association of certain dietary factors and xenobiotic intake with the incidence of CRC. Nevertheless, how these dietary factors impact the first stages of intestinal mucosa damage is still uncertain. This study aimed at exploring the associations of relevant dietary factors with the gut microbiota of control individuals and subjects diagnosed with intestinal polyps. A total of 60 volunteers were recruited, clinically classified according to colonoscopy criteria and interviewed using food frequency questionnaires (FFQs). The nutritional status of each volunteer was determined and the intake of dietary xenobiotics was quantified. The relative abundance of faecal microbiota taxonomic groups was obtained through 16S rRNA gene sequencing. The association of dietary factors and xenobiotics with faecal microbiota composition showed differences according to the clinical diagnosis group. Our results showed that the intake of red meat (≥50 g day-1) and total polycyclic aromatic hydrocarbons (PAHs) (≥0.75 μg day-1) was associated with a decreased abundance of the family Bacteroidaceae and an increased abundance of Coriobacteriaceae in control subjects. The intake of the heterocyclic amines 2-amino-1-methyl-6-phenylimidazo(4,5-b)pyridine (PhIP) (≥40 ng day-1) and 2-amino-3,8 dimethylimidazo(4,5,f) quinoxaline (MeIQx) (≥50 ng day-1) was associated with a decreased abundance of Akkermansiaceae in the control diagnosis group. Moreover, N-nitroso compounds (NOCs), nitrites (≥1.69 mg day-1) and N-nitrosodimethylamine (NDMA) (≥0.126 μg day-1) were associated with a decreased abundance of Bifidobacteriaceae. The intake of ethanol (≥12 g day-1) in the polyps group was associated with an increased abundance of Peptostreptococcaceae and a decreased abundance of Veillonellaceae. Moreover, linear regression analyses allowed us to identify ethanol, calcium, bioactive compounds such as flavonoids, stilbenes, cellulose, phenolic acids or total polyphenols, and dietary xenobiotics such as PhIP and MeIQx, the NOC N-nitrosopyrrolidine (NPYR) or the total PAHs as potential predictors of faecal microbiota group abundances. These results indicated that the consumption of milk, red meat, processed meat and ethanol and the intake of polyphenols, dietary PAHs, HAs and NOCs are associated with specific groups of the intestinal microbiota, depending on the clinical diagnosis group.

AN ANALYSIS OF THE CONTENT OF POLYCYCLIC AROMATIC HYDROCARBONS IN SMOKED CHEESES

Background. Traditional cheeses, including smoked products, are one of the most recognizable products among consumers, due to their taste and relationship with regional history. However, the smoking process can be a source of cheese contamination due to the presence of some toxic compounds in smoke. The aim of the study was to analyze the content of polycyclic aromatic hydrocarbons (PAHs) in traditional smoked and non-smoked cheeses, as well as in industrial smoked cheeses (23 samples in total). The content of PAHs (18 compounds) was determined using the modified QuECHERS method with final detection by gas chromatography coupled with mass spectrometry. Results and conclusion. The total PAH content varied and ranged from 119.0 to 257.6 μg/kg in traditional non-smoked cheeses, 137.8 ÷ 625.1 μg/kg in traditional smoked cheeses and 131.8 ÷ 277.7 μg/kg in industrial smoked cheeses. Indeno[1,2,3-c,d]pyrene, dibenzo[a,h]anthracene, benzo[g,h,i]perylene were not detected in any of the analyzed cheese samples, while naphthalene, 2-methylnaphthalene, 1-methylnaphthalene, acenaphthylene, fluorene, phenanthrene, anthracene, fluoranthene were identified in all the tested samples. Benzo[a]pyrene was identified in nine cheese samples (6/11 samples of traditional smoked cheeses, one sample of non-smoked cheese and two out of seven samples of smoked cheeses from industrial production), in the range of 1.5 ÷ 6.5 μg/kg. The occurrence of the so-called PAH markers was found in both smoked and non-smoked cheeses, which suggests that contamination with the hydrocarbons being examined might occur as early as at the raw material production stage, before the smoking process. However, no statistically significant differences were found between the three groups of cheeses, both in the total PAH and the PAH4 sum.

Effect of Smoking and Grilling on Polycyclic Aromatic Hydrocarbons in Ghanaian Tilapia.

The study assessed 18 Polycyclic Aromatic Hydrocarbons (PAHs) in O. niloticus (Nile tilapia) sampled from an aquaculture cage (farm) and a wild catch. The PAHs in fish samples were analysed using Gas Chromatography-Mass Spectrometry. Four PAHs (in order of levels: Indeno [1,2,3-cd] pyrene > Anthracene > Perylene > Pyrene; 100-0.8 µg/kg) and only one PAH (Pyrene: 4 µg/kg) were detected in raw samples from the cage and wild catch respectively. Chargrilling significantly increased Pyrene levels after cooking (wild: 4-11 µg/kg; cage: 5-23 µg/kg, p < .05), and likewise Anthracene levels in cage samples (13-153 µg/kg) but decreased Indeno [1,2,3-cd] pyrene levels from 100 ± 20 to 1.2 ± 0.2 µg/kg in cage samples. Smoking significantly increased 13 to 15 PAH congeners' levels (from < 1.0 up to 340 µg/kg) and total PAHs (wild: 4 to 840 µg/kg; cage: 110 to 560 µg/kg), and decreased Indeno [1,2,3-cd] pyrene (100 to 1.3 µg/kg) in cage samples but showed no effect on Benzo [g, h, i] perylene and Dibenzo [a, h] anthracene levels in all samples. For smoked samples, Benzo [a] pyrene and PAH4 (Benzo [a] anthracene, Chrysene, Benzo [b] fluoranthene, and Benzo [a] pyrene) exceeded the respective maximum permissible limits of 2 µg/kg and 12 µg/kg, and significantly influenced the levels of carcinogenic PAHs (CPAH, 135-170 µg/kg). Nevertheless, the Excess Cancer Risk (ECR) estimates, from a conservative approach, were far below the threshold (10-4), implying that consuming smoked or grilled tilapia from the study site is safe.

Izdržljivost na pritisak i uticaj na propustljivost tretiranih otvora bušotina kod delimične zamene cementa u proizvodnji betona

This study examines the compressive strengths and leachability effects of treated drill cuttings as a partial replacement of cement in concrete production. Workability tests on various water-binder ratios (w/b) on the fresh concrete showed that an optimum w/b of 0.5 was adequate for the concrete to be workable. Replacement levels of 0, 5, 10, 15, 20, and 25% were used to produce cement-drill cuttings concrete at a 1:1.5:3 mix ratio. The blended concrete gave a compressive strength in the range of 26.20N/mm 2 for 5% to 22.46N/mm 2 for 20% replacement levels at 28 days curing time, more than the minimum compressive strength of 20N/mm 2 and 25N/mm 2 specified for concrete strength class C/20 and C/25, respectively. The strength activity index of 90.56, 98.76, 89.05, 98.05, and 77.64% for 5, 10, 15, and 20% replacement levels at 28 days of curing time was obtained surpassing the minimum 75% specified for normal concrete by the code. The wet/dry durability effects of the blended concrete at any replacement level passed the structural integrity with less than 5% of the structural integrity of the material lost. The chloride and total polycyclic aromatic hydrocarbons (TPAHs) leachability effects both met the DPRs target values for reusable materials. The study has shown that drill cuttings have a good pozzolanic effect on concrete, especially when activated at the temperature of 500oC for 180 minutes. It also shows that treated drill cuttings could replace cement up to 20% by weight to produce concrete of adequate strength using a w/b ratio of 0.5 and mix ratios of 1:1.5:3. The study has also shown that treated drill cuttings replaced with cement to produce concrete which is durable to both wet/dry and leaching effects of chlorides and TPAHs to the environment.

The Unignorable Near-ground PM2.5, UFP, PAHs, and BC Levels around a Traffic Prohibited Night Market

In some special densely populated areas, the background atmospheric fine particulate matter (PM2.5) concentration is very high, which makes near-ground (NG) exposure a major problem endangering human health. In our study, the night market in Chiayi City was selected as the research object and collected the 24-hour PM2.5 samples through the federal reference method (FRM), characterizing the mass concentration, water-soluble ionic components, carbon specious, metal compositions and source contributions of PM2.5. To better analyze the contribution of traffic sources under different sampling conditions, the mobile real-time monitoring system was used to analyze the quality of NG-PM2.5, the number of ultra-fine particles (UFP), the concentration of black carbon (BC) and total polycyclic aromatic hydrocarbons (PAH) before and after the traffic restriction. Results indicated the concentration of PM2.5 was 7.26–58.6 mg m-3. In chemical analysis, secondary contents e.g., carbonaceous and ionic components accounted for ~60% of the PM2.5, supporting the importance of long-range transport. However, the traffic contribution accounted for ~30% and hardly changed between different samples, which was not conducive to source apportionment. Through traffic restriction, it was found that all kinds of pollutants increased significantly before restriction, and even after restriction, the concentrations of PM2.5 and BC increased 131% and 151% in low concentration season. In the high concentration season, the traffic restriction significantly reduced the NG-UFP and NG-PAH concentration by 27% and 55%, respectively, but NG-BC and NG-PM2.5 was almost unaffected. Therefore, besides the contribution of traffic source, emissions from cooking activities are very important for the increase of NG-PM2.5 levels in the night market area.

Sources, Compositions, and Health Risks of PM2.5-bound PAHs at the Rural Area along with the “Coal to Gas” Law

The “Coal to Gas” (CTG) policy in north China markedly altered the characteristics of polycyclic aromatic hydrocarbons (PAHs) in PM2.5. Existing researches about CTG impacts on components, sources, and health risks of PM2.5-bound PAHs mainly focused on metropolitan area, whereas they were lacking in rural area of north China. Here, we deployed an intensive observation in winter of 2020 at a rural site in the central area of the Beijing-Tianjin-Hebei (BTH) region. A positive matrix factorization (PMF) model and an incremental lifetime cancer risk (ILCR) model were utilized to examine the PAH sources and health risks. Higher daily average PM2.5 of 81.5 µg m–3 in the sampling period than 75 µg m–3 of the National Air Quality Standard Grade II indicated the air pollution in rural area was still serious. The total PAHs increased obviously from diurnal 86.2 ng m–3 to nocturnal 151 ng m–3 because of the nocturnal high intensity of heating, with the increases of 20.7%, 85.5%, and 76.3% for low, medium, and high molecular weight PAHs, respectively. Vehicular exhaust (VE), coal burning (CB), industrial source (IS), biomass burning (BB), and oil spill and leakages (OSL) were the main PAH contributors, with the average daily contributions of 32.7%, 21.5%, 18.3%, 15.9%, and 11.6%, respectively. Lower CC contribution of 27.6% in winter of 2020 than 27.6% in winter of 2019 indicated the positive role of CTG policy. However, the nocturnal CC fraction increased by 680% compared with the diurnal value, and CC had become the largest contributor in the nighttime. BB contribution was up to 18.3%, evidencing that biomass utility should be managed in term of the biomass burning was prohibited in BTH rural area. Moreover, the nocturnal average BaPeq equivalent concentration exhibited higher levels than those in the daytime. The nocturnal ILCR values of adults and children was 9.35 × 10–6 and 2.66 × 10–6, exceeding the acceptable threshold, suggesting there was a potential carcinogenic risk.

Bioaccumulation of Polycyclic Aromatic Hydrocarbons (PAHs) in simping scallops (Placuna placenta) from the Waters of Socah and Ujungpangkah, East Java

The study aimed to investigate the bioaccumulation of Polycyclic Aromatic Hydrocarbons (PAHs) in Placuna placenta scallops from Socah and Ujungpangkah waters in East Java, Indonesia. The research involved sampling from Station 1 at Ujungpangkah and Station 2 at Socah waters. Water, sediment, and Simping scallops were sampled twice, in December 2018 and January 2019. The analysis method used Gas Chromatography-Mass Spectrometry (GC-MS). The analysis results indicated that the total PAHs concentration was higher in Ujungpangkah waters compared to Socah waters. In line with the result of sediment samples, five types of compounds naphthalene, acenaphthene, benzo[ghi]perylene, 2-methylnaphthalene, and 1-methylnaphthalene were found to be more abundant in Ujungpangkah, while Socah waters exhibited the highest concentration of four compounds naphthalene, acenaphthene, 1- methylnaphthalene, and 2-methylnaphthalene. When examining the scallop samples, the highest compound concentrations detected at both locations matched those in the water samples. The Bioconcentration Factor (BCF) value, representing the accumulation of PAHs in Placuna placenta scallops, was higher when obtained from the water than the sediment. In summary, this study revealed varying PAH levels between the two sampling locations, with Ujungpangkah exhibiting higher concentrations than Socah. The results also demonstrated the ability of Placuna placenta scallops to accumulate PAHs from the surrounding water, highlighting their role as bioindicators of environmental contamination.

Effects of pyrolysis temperature and pressure on agronomic properties of biochar

This study focused on identifying the effect of pyrolysis temperature and pressure for lignocellulosic biomass on agronomic properties of biochar. For this purpose, two biomasses (vine shoots -VS and corn stover -CS) were pyrolyzed at different temperatures (350 and 500 °C) under different pressures (0.1 and 0.5 MPa) for a residence time of 60 min. Agronomic properties of biochars (including stability, pH, CEC, EC, bulk density, surface properties, and water holding capacity) were determined. Pyrolysis temperature impacted greatly on the biochar stability and the textural properties. The dependence of other properties of biochars on pressure and temperature varied as a function of the type of feedstock. In addition, the effects of pyrolysis temperature and pressure on 16 US EPA PAH concentration in biochar were also investigated. The PAH concentrations ranged between 0.822 and 5.112 mg kg−1. On average, VS-derived biochar had higher PAH concentrations than CS-derived one. The structural differences in biomass played a key role in determining the effect of pyrolysis conditions on total PAH concentration.

Health risk assessment of potentially harmful substances from fly ashes generated by coal and coal waste combustion

Lignite and coal waste used as feed fuels in thermal power plants (TPPs) and semi-industrial fluidized bed boiler (FBB), as well as their representative fly ashes (FAs), were examined. Fly ashes were compared employing anions and cations content in correspondent water extracts, trace elements and polycyclic aromatic hydrocarbon concentrations, as well as health risk assessments of substances known to be of concern for public health. Fluoride and sulfate contents in water extracted FAs are far below the legislation limits for waste, classifying all investigated FAs as non-hazardous. Among investigated trace elements, Cd content is the lowest, while Mn content is the highest. The highest enrichment ratios are noticed for As, Pb, Hg, Cu, V and Cr. The results indicate that total PAHs content is elevated in FA from the combustion of coal waste (AFB), with fluoranthene prevailing. The cancer risk of As and the non-cancer risk of As and Ni in some FAs surpass their respective permissible limits. The incremental lifetime cancer risk of an adult population indicates a potential PAHs risk in AFB, whereas all other fly ashes are within safe limits.

Polycyclic Aromatic Hydrocarbons (PAHs) in household dust: The association between PAHs, Cancer Risk and Sick Building Syndrome

In this study, indoor dust samples were collected from 40 houses in Shiraz; Iran, and analyzed to determine 16 Polycyclic Aromatic Hydrocarbons (PAHs) using Gas chromatography–mass spectrometry (GC-MS). The study participants completed the questionnaires consisting of a series of questions for collecting information about symptoms of sick building syndrome and parameters affecting PAHs concentrations (including traffic congestion in the area, floor level, house renovation, building age, etc.). The total PAHs concentrations in the settled dust samples ranged from 31 to 453 ngg−1 so that, phenanthrene, naphthalene and fluoranthene were the predominant congeners. Diagnostic ratios and principal component analysis (PCA) indicated the predominance of vehicular (especially diesel vehicle emissions) and cooking emissions, as the two major sources of PAHs, in indoor dust. The results of statistical analysis showed a significant association between the total PAHs concentrations and SBS symptoms (headache, skin dryness, itching, and inflammation). In addition, based on health risk assessment, the mean ILCR (Incremental Lifetime Cancer Risk) value was reported to be 3.85 × 10−5 for adults and 4.36 × 10−5 for children, indicating potential cancer risk as a result of exposure to household dust containing PAHs. The findings of this study can provide useful information to improve the quality of the indoor environment of houses.

Release of PAH from Secondary Products Made from End-of-Life Tire Recyclates into 20% Aqueous Ethanol as Assessment of Human Dermal Absorption

Compliance with the legal limits set at the European level for the content of polycyclic aromatic hydrocarbons (PAH), which are harmful to human health and the environment, is of central importance for the recycling of rubber, particularly end-of-life tires (ELT), into secondary products, e.g., elastic fall protection mats or anti-slip mats for the transport sector. However, different regulations associated with different analytical methods apply to newly produced tires on the one hand and secondary products made from ELT on the other. Given these discrepancies, ELT can potentially contain levels of PAH, which can be problematic when reused in consumer products. The total PAH content, however, is not without doubt a reliable risk indicator, which should ultimately be based primarily on the transfer of the substances from the product into the skin of human beings or their release into the environment. Accordingly, additional studies are required to determine the extent to which migration-based measurements are more suitable for risk assessment and how the PAH content correlates with migration. Complementing the recently published results of PAH content in different types of ELT, this study investigates the release of PAH for a range of typical secondary materials composed entirely or partly of ELT. In the present study, migration tests with 20% aqueous ethanol were applied, a methodology that has been shown in previous investigations by others to reflect human skin exposure well, and the resulting migration rates of PAH are determined.

Assessment of environmental risk related to the polycyclic aromatic hydrocarbons (PAH) in the sediments along the eastern Adriatic coast

Polycyclic aromatic hydrocarbons (PAH) were investigated in the sediments at 24 locations in the coastal area of Adriatic Sea. Total PAH concentrations ranged from 14,98 to 26145,62 µg kg-1, with the highest levels determined in the sediments of Šibenik Bay and the lowest in the sediment near Island of Pag. Unsubstituted PAH were prevailing PAH group in the sediments from the Šibenik Bay and in the Coastal area, while methyl-substituted PAH were dominant group in the sediments of the Kaštela Bay. In order to estimate the possible toxicological significance of PAH concentrations, Sediment Quality Assessment was done according to three different sets of sediment quality guidelines. A high environmental risk was calculated for each station in Šibenik Bay; for the station in vicinity of the Industrial port of Split and for the two stations in Coastal zone. Low environmental risk was determined in less urbanised areas such as Island of Pag. Sediment extracts were further analysed for acute toxicity by measurements of decrease in bioluminescence upon exposure to sediment extracts. Obtained results show disagreement between sediment toxicity predicted upon PAH levels in sediment and experimentally obtained sediment toxicity. Sediment extracts in which low PAH levels were measured showed high acute toxicity indicating that concentrations of PAH alone are a poor indicator of sediment toxicity. Correlation analysis between concentrations of specific PAH compounds and toxicity revealed the strongest association between acute sediment toxicity and sulphur-containing PAH suggesting the S-PAH should be considered in sediment toxicity assessment.

Emission and distribution profiles of polycyclic aromatic hydrocarbons in solid residues of municipal and industrial waste incinerators, Northern Vietnam.

The concentrations and profiles of 18 polycyclic aromatic hydrocarbons (PAHs) in particulate matter (PM10), fly ash (FA), and bottom ash (BA) were examined in three incineration residues. Samples were collected from different municipal and industrial solid waste incinerators in Northern Vietnam. The average concentrations of total PAHs in PM10, fly ash, and bottom ash were 9.55 × 103ng/Nm3, 215 × 103ng/g, and 2.38ng/g, respectively. Low-molecular-weight PAHs (2 to 3 rings) were predominant in most samples. The emission factor of total PAHs decreased in the order of FA > BA > PM10. A higher concentration of total PAHs was found in industrial facilities than that in municipal ones. The high carcinogenic proportion of PAHs together with significantly high annual emissions reflect the high pollution risk to the ecosystem by PAHs in the case of reuse of incineration ashes (e.g., brick production). Regarding the carcinogenic risk of PAH-bounded ashes or particles, calculations from this study imply the significant threat for workers who have been manipulated in the incineration facilities, directly exposed to fly and bottom ashes. Meanwhile, the risk from PAH-bound particulate was not considered a significant threat for both normal adults and children. Further study on PAHs contained in incinerator waste dumps should be conducted in Vietnam to assess the potential contamination risk of these incineration by-products.

Ecotoxicological characteristics and properties of zinc-modified biochar produced by different methods

Despite the dynamic progress of BC engineering, there is a lack of knowledge on the toxicity and environmental impact of modified BC. The aim of this study was the ecotoxicological evaluation of BC modified with zinc (Zn) using different methods: impregnation of feedstock with Zn before pyrolysis (PR), impregnation with Zn after pyrolysis (PS) and impregnation with Zn after pyrolysis with an additional calcination step (PST). The ecotoxicological assessment was based on tests with invertebrates (Folsomia candida, Daphnia magna) and bacteria (Aliivibrio fischeri). The post-treated and calcined composites had a higher content of total (Ctot) PAHs (144–276 μg kg−1) than pre-treated BC-Zn (68–157 μg kg−1). All BC-Zn treatments stimulated the reproduction of F. candida at the lowest BC dose (0.5%) by 4–24%. Increasing the biochar dose to 1% and 3% retained the stimulating effect of the pre-modified biochars (from 19 to 41%). Pre-modified BC-Zn reduced the luminescence of A. fischeri from 40% to 80%. Post-treated BCs reduced bacterial luminescence by 99%, but the calcination step limited the toxic effects to the level observed for the control. Post-treated BCs had a toxic effect on D. magna, with EC50 values ranging from 433 to 783 mg L−1. The ecotoxicity of composites depends on modification methods, BC dose and pyrolysis temperature. The application of limiting conditions for HM leaching (i.e., pre-modification, calcination) increased the safety of using Zn-biochar composites.

A Risk-Benefit Analysis of First Nation's Traditional Smoked Fish Processing.

First Nations (FN) communities have traditionally used smoke to preserve fish for food security purposes. In this study, an assessment of chemical and microbiological food safety, together with nutritional quality, was conducted on fish preserved using traditional smoke processing. High-molecular-weight polycyclic aromatic hydrocarbons (PAH) residues accounted for only 0.6% of the total PAH in traditionally fully smoked salmon, and Benzo(a)pyrene (B(a)P) was not detected in the FN smoked or commercial smoked fish, respectively. The antimicrobial activity of the solvent extracts derived from smoked fish towards Listeria innocua was very low but detectable. The practice of using full and half-smoked processing for fish reduced all of the fatty acid concentrations and also minimized the further loss of essential omega-3 fatty acids to a greater extent than non-smoked fish during storage (p < 0.05). This finding corresponded to lower (p < 0.05) lipid oxidation in smoked fish. We conclude that the benefits of reducing lipid oxidation and retaining essential fatty acids during storage, together with a potentially significant reduction in Listeria contamination, are notable benefits of traditional smoke processing. Although B(a)P was not detected in FN smoked fish, attention should be given to controlling the temperature and smoking period applied during this processing to minimize potential long-term risks associated with PAH exposure.

Exposures to Polycyclic Aromatic Hydrocarbons and Their Mitigation in Wildland Firefighters in Two Canadian Provinces.

We aimed to characterize polycyclic aromatic hydrocarbons (PAHs) in the breathing zone and on the skin of wildland firefighters and to assess their contribution to urinary 1-hydroxypyrene (1-HP) over repeated firefighting rotations. We asked if improved skin hygiene or discretionary use of an N95 mask would reduce absorption. In collaboration with wildfire services of two Canadian provinces, Alberta and British Columbia (BC), we recruited wildland firefighters from crews willing to be followed up over successive rotations and to be randomly assigned to normal practice, enhanced skin hygiene (ESH), or ESH plus discretionary use of an N95 mask. We collected spot urine samples at the beginning and end of up to four rotations/firefighter. On designated fire days, as close as possible to the end of rotation, we collected skin wipes from the hands, throat, and chest at the beginning and end of the fire day and, in BC, start of fire-day urine samples. Volunteers carried air monitoring pumps. Participants completed questionnaires at the beginning and end of rotations. Exposure since the start of the fire season was estimated from fire service records. Urinary 1-HP was analyzed by LC-MS-MS. Analysis of 21 PAHs on skin wipes and 27 PAHs from air sampling was done by GC-MS-MS. Statistical analysis used a linear mixed effects model. Firefighters in Alberta were recruited from five helitack crews and two unit crews, and in BC from two unit crews with 80 firefighters providing data overall. The fire season in BC was very active with five monitored fire days. In Alberta, with more crews, there were only seven fire days. Overall, log 1-HP/creatinine (ng/g) increased significantly from the start (N = 145) to end of rotation (N = 136). Only three PAHs (naphthalene, phenanthrene, and pyrene) were found on >20% of skin wipes. PAHs from 40 air monitoring pumps included 10 PAHs detected on cassette filters (particles) and 5 on sorbent tubes (vapor phase). A principal component extracted from air monitoring data represented respiratory exposure and total PAH from skin wipes summarized skin exposure. Both routes contributed to the end of rotation urinary 1-HP. The ESH intervention was not demonstrated to effect absorption. Allocation of an N95 mask was associated with lower 1-HP when modeling respiratory exposure (β = -0.62, 95% CI -1.15 to -0.10: P = 0.021). End of rotation 1-HP was related to 1-HP at the start of the next rotation (β = 0.25, 95% CI 0.12 to 0.39: P < 0.001). Exposures to PAHs during firefighting were significant, with samples exceeding the American Conference of Governmental Industrial Hygienists Biological Exposure Index for 1-HP suggesting a need for control of exposure. PAH exposure accumulated during the rotation and was not fully eliminated during the break between rotations. Both respiratory and skin exposures contributed to 1-HP. While improved skin hygiene may potentially reduce dermal absorption, that was not demonstrated here. In contrast, those allocated to discretionary use of an N95 mask had reduced 1-HP excretion. Wildland firefighters in North America do not use respiratory protection, but the results of this study support more effective interventions to reduce respiratory exposure.

A Snapshot on the Occurrence and Risk Assessment of Organic Pollutants in an Urban River

A snapshot screening was carried out in an urban river at the end of a dry period in the water and sediments to assess the presence and environmental risk for the following CECs: paracetamol, ibuprofen, diclofenac, clofibric acid, carbamazepine, ofloxacin, caffeine, tonalide, galaxolide, and bisphenol-A. Concomitantly, the occurrence and environmental risk of sixteen PAHs congeners, six indicator PCBs, and twelve dioxin-like PCBs were evaluated in sediments. The most abundant and ubiquitous CECs were bisphenol A (BPA) and caffeine, and the total contents in the surface water varied between 90.95–212.18 and 3.17–167.38 ng·L−1, respectively. The concentrations found in lixiviates ranged from 134.94–772.85 (BPA) and 14.43–92.60 ng·L−1 (caffeine). Other CECs were detected in lower concentrations, and their presence varied between sampled sites. Values of total PAHs congeners in sediment varied between 10.39–52.91 ng·g−1 dw. The majority of the detected PAHs seem to have a pyrolitic origin with a small petrogenic contribution. Total PCBs’ concentrations ranged from 5.06 to 6.13 ng·g−1 dw. Despite the relatively low concentration of most of the detected compounds, the overall environmental risk, considering the screened compounds altogether, cannot be considered negligible. The obtained results are discussed in terms of other data available (though highly dispersed) in the literature. A four-color alert system is included to inform about the level of risk associated with the amount of each CEC, PAH, and PCB.

A baseline study of polycyclic aromatic hydrocarbons distribution, source and ecological risk in Zhanjiang mangrove wetlands, South China

Polycyclic aromatic hydrocarbons (PAHs) are widespread environmental contaminants and pose a severe threat to human health. Here, 38 surface sediment samples collected from the Gaoqiao mangrove wetland in Zhanjiang, south China, were analyzed to determine 16 Environmental Protection Agency (EPA) priority PAHs. Total PAHs concentrations ranged from 33.5 µg/kg to 404.8 µg/kg with an average of 147.7 ± 77.7 µg/kg, inferring a moderate pollution level. Three and four-ring compounds dominated the PAHs composition patterns. Significant positive correlations were observed between the PAHs and the physicochemical properties of the sediments. According to the characteristic molecular ratio method, PAHs in sediments were mainly derived from combustion sources, including the incomplete combustion of liquid fossil fuels, grass, wood, and coal. The result based on the PMF model indicates that the primary combustion sources of PAHs are coal combustion, diesel-powered vehicles, biomass combustion and gasoline-powered vehicles, with a share of 39.01%, 25.21%, 12.72% and 10.48%, respectively. The petrogenic source contributes 12.58% PAHs to the sediments. The mean effects range median quotient (m-ERM-Q) and toxic equivalent method (TEQ) indicate a low comprehensive ecological risk of PAHs in the study area. Still, the evaluation results of effects range low (ERL) suggest that PAHs in the sediment would occasionally have adverse biological effects. Therefore, this situation demands attention and calls for protection strategies in the processes of urbanization and industrialization in south China.

Occurrence, sources, and potential risk of polycyclic aromatic hydrocarbons in southern Xinjiang, China

Abstract Polycyclic aromatic hydrocarbons (PAHs) are environmental pollutants of global concern, mainly originating from industrial activities, biomass combustion, and vehicle emissions. With the acceleration of industrialization, the surrounding environment of the industrial area may have potential health effects on the population. Therefore, we focused on the occurrence, source, and health risk assessment of PAHs in soil, plants, and water near industrial areas in southern Xinjiang, China. The occurrence of PAHs in different soil layers (0–10, 10–30, and 30–50 cm) was studied, with PAHs mainly concentrated in the topsoil (11.50–34.68 ng/g). In plants, PAHs varied from 56.63 to 597.28 ng/g, with the highest concentrations in reed (267.29–597.28 ng/g). Total PAHs in water ranged from 4183.85 to 24803.45 ng/L, with an average of 10,240 ng/L. 3-ring PAHs were the dominant species in soil, plants, and water with 55, 69, and 59%, respectively. PAHs isomer ratio results indicated that PAHs in soil, plants, and water mainly came from fossil fuels and biomass combustion. Incremental lifetime cancer risk estimation results demonstrated that adults might face higher potential health risks than children. Adults’ dermal contact was the dominant route of exposure, while oral ingestion was the dominant exposure pathway for children. The total carcinogenic risk value of corn is much higher than that of walnuts and red dates, indicating that PAHs pollution in corn must be taken seriously. The results can clarify the local pollution situation, and provide suggestions for improving pollution prevention and control measures.