The Occurrence of 16 EPA PAHs in Food – A Review

Occurrence and toxicity of polycyclic aromatic hydrocarbons (PAHs) have been extensively studied in countries all over the world. PAHs generally occur in complex mixtures which may consist of hundreds of compounds. The U.S. Environmental Protection Agency (EPA) proposed in the 1970 to monitor a set of 16 PAHs which are frequently found in environmental samples. This article reviews the suitability of the 16 EPA PAHs for the assessment of potential health threats to humans stemming from the exposure to PAHs by food ingestion. It presents details on analysis methods, the occurrence of PAHs in food, regulatory aspects, and related risk management approaches. In addition, consideration is given to newer evaluations of the toxicity of PAHs and the requirements for risk assessment and management stemming from them.     

PAH and other emissions from burning of JP-8 and diesel fuels in diffusion flames

Jet fuel JP-8 is of technical interest to the military aviation industry. JP-8 is now the single battlefield fuel for all US Army and Air Force equipment, replacing gasoline altogether and gradually replacing diesel fuel. Hence, emissions from the combustion of this fuel are the subject for this investigation. The emissions from the combustion of JP-8 fuel are examined and are compared to those from diesel fuel No. 2, burned under identical conditions. Combustion occurred inside a laboratory furnace in sooty diffusion flames, under adverse conditions that typically emit large amounts of products of incomplete combustion (PIC). Under such conditions, even compounds that otherwise might appear only in trace amounts were present in sufficient quantities for detection. The study reports on emissions of CO, light volatile organic compounds, semi-volatile organic compounds with an emphasis on polycyclic aromatic hydrocarbons (PAH), particulate emissions, oxides of nitrogen (NO_x) and oxides of sulfur (SO₂). Some PAH compounds are suspected of posing a threat to human health, benzo[a]pyrene being listed as a bio-accumulative toxin by the EPA. An afterburner was also used to examine the effects of longer furnace residence time. Results have demonstrated that PAH emissions from the combustion of diesel fuel were higher than those of JP-8, under most conditions examined. Moreover, as the temperature of the primary furnace was increased, in the range of 600–1000 °C, most of the emissions from both fuels increased. Particulate emissions were reduced by the afterburner, which was operated at 1000 °C, only when the primary furnace was operated at the lowest temperature (600 °C), but that condition increased the CO emissions. Overall, transient combustion of these two fuels, burning in laminar and sooty diffusion flames, did not reveal major differences in the emissions of the following PIC: C1–C4 light aliphatic hydrocarbons, PAH, CO and particulate matter.     

煤热解转化排放物对环境和健康的影响

讨论了煤热解转化过程中主要排放物对环境和健康的影响,诸如CS2、COS、H2S、NH3、HCN和BTX等排放物,其毒性对植物产生潜在的影响。文中列出中国发表的环境优先污染物“黑名单”。癌症是从事煤热解转化工厂工人的主要隐患。多环芳香碳氢化合物和一些有机化合物,如芳胺类、亚硝胺类和苯系化合物教师主要的潜在致癌化合物,文中讨论了其生成、分子结构及其致癌活性,并举职业危害为例证。     

Presence and control of polycyclic aromatic hydrocarbons in petroleum coke drying and calcination plants

Storage, shipment, handling, as well as drying and calcination of petroleum cokes might create serious health risks. This material should be processed and handled with care not only because of the excessive dust emissions it causes, but also because it may emit hazardous and carcinogenic volatile compounds. In this study, polycyclic aromatic hydrocarbon (PAH) emissions from a petroleum coke drying and calcination unit in Turkey were investigated. Rotary kiln exhaust gases were found to contain 10 of the 16 EPA priority PAHs. These emissions were identified and evaluated by using the Turkish regulatory limits after certain pollution control measures were implemented. For control of PAHs and other incomplete combustion products in the stack gases incinerators equipped with liquefied petroleum gas (LPG) burners were installed into the drying and calcination gas outlet ducts.     

Time to Say Goodbye to the 16 EPA PAHs? Toward an Up-to-Date Use of PACs for Environmental Purposes

The 16 EPA PAHs have played an exceptionally large role above all in environmental and analytical sciences in the last 40 years, but now there are good reasons to question their utility in many circumstances even though their use is so established and comfortable. Here we review the reasons why the list has been so successful and why sometimes it is seen as less relevant. Three groups of polycyclic aromatic compounds (PAC) are missing: larger and highly relevant PAHs, alkylated PACs, and compounds containing heteroatoms. Attempts to improve the situation for certain matrixes are known and here: (1) an updated list of PAHs (including the 16 EPA PAHs) for the evaluation of the toxicity in the environment (40 EnvPAHs); (2) a list of 23 NSO-heterocyclic compounds and 6 heterocyclic metabolites; and (3) lists of 10 oxy-PAHs and 10 nitro-PAHs are proposed for practical use in the future. A discussion in the scientific community about these lists is invited. Although the state of knowledge has improved dramatically since the introduction of the 16 EPA PAHs in the 1970s, this summary also shows that more research is needed about the toxicity, occurrence in the environment and chemical analysis, particularly of alkylated PAHs, higher molecular weight PAHs and substituted PACs such as amino-PAHs, cyano-PAHs, etc.. We also suggest that a long overdue discussion of an update of regulatory environmental PAH analysis is initiated.     

A GIS-based national emission inventory of major VOCs and risk assessment modeling: Part II — quantitative verification and risk assessment using an air dispersion model

We compiled contour maps of the concentrations of major volatile organic compounds (VOCs) and corresponding chronic inhalation and carcinogenic risks in South Korea for the year 2004. We used the CALPUFF modeling system, an atmospheric dispersion model, to calculate the concentrations of five species of VOCs (benzene, ethylbenzene, styrene, toluene, and xylene). This modeling approach was used to validate the emission rates estimated in Part I of this study. The predicted concentrations show good overall agreement with the observed concentrations. In terms of risk assessment, we studied the chronic and carcinogenic effects on human health based on toxicity data and predicted concentrations of VOCs in ambient air. Risk levels were influenced by regional characteristics and spatial emission patterns. The results of such risk assessments could be used in support of air quality management in South Korea.     

Personal Exposure of Children to Particle-Associated Polycyclic Aromatic Hydrocarbons in Tianjin,China

Polycyclic aromatic hydrocarbons (PAHs) associated with fine particles are harmful to human health, particularly to children, who are most vulnerable. To evaluate the respiratory exposure of children to particle-associated PAHs properly, personal air sampling near breathing zone of 36 schoolchildren were conducted in Tianjin, China. Sixteen priority PAHs designated by the United States Environmental Protection Agency were measured using GC-MS. The average concentrations of personal exposure to ∑₁₆PAH were 27.31 ± 3.91 ng/m³ in summer and 58.18 ± 24.68 ng/m³ in winter. Moreover, PAH profiles were studied and the results showed NAP, BbF, and IPY were the most abundant PAHs. Five rings PAH species made up the largest proportion, accounting for 25.7% in summer and 32.6% in winter. Diagnostic ratios and principal component analysis indicated combustion activities were the major source for children exposure to particle-associated PAHs in this study. According to the risk assessment results, the inhalation exposure risk for children were higher than the acceptable risk level of 10–⁶, indicating the health issues of children should be paid more attention. On the basis of sensitivity analysis results, further research should be done to improve the inhalation cancer slope factor of BaP and the concentration distribution of PAHs in order to improve the accuracy of the health risk assessment.     

WHERE ARE THE LIMITS OF THE GAS-PHASE FLUORESCENCE ON THE POLYCYCLIC AROMATIC COMPOUND ANALYSIS?

The aim of this work has been centered on the development of a detection system which could be useful to determine polycyclic aromatic hydrocarbon (PAH) emissions in power generation processes where PAHs are released to the atmosphere in the gas phase. In this way, a suitable sensor based on gas phase fluorescence spectroscopy was designed to facilitate the PAH analysis, avoiding previous steps necessary to determine liquid samples such as extraction, concentration, and cleaning. This gas cell was applied for two experimental installations at laboratory scale. One of them was used to determine adsorption capacities and breakthrough curves of PAH binary mixtures and the other installation allowed the separation of PAH mixtures by using, previous to the gas phase fluorescence spectroscopy, a packed column.     

Characterization of PM2.5-Bound Polycyclic Aromatic Hydrocarbons in the Ambient Air of Győr,Hungary

ABSTRACT

In Hungary, the nationwide monitoring of PM10-bound polycyclic aromatic hydrocarbons (PAHs) in ambient air is great importance for a number of reasons related to human health, the environment and compliance with European Union legislation. However, the measurement of PAH concentrations in PM2.5 aerosol fraction has not been carried out. Therefore, the concentration, distribution and sources of PM2.5-bound PAHs at different urban sites of Gy?r were investigated in a heating season. The total PAH concentrations (sum of 19 individual PAH compounds) ranged from 1.32 to 37.27 ng/m³ with the mean value of 10.54 ng/m³. The high molecular weight PAHs with 5 and 6 aromatic rings were the most abundant PAHs in PM2.5 aerosol samples, which averaged 82% of total PAHs. Using benzo(a)pyrene (BaP) equivalent approach on the concentration data of carcinogenic PAH species, BaP and indeno(1,2,3-cd)pyrene contributed the highest carcinogenic exposure equivalent (1.25 and 0.19 ng/m³ on average). However, the incremental lifetime cancer risk (ILCR) values for resident children and adults indicated low-potential cancer risk (ILCR < 10^?6). The source apportionment results reflected that the major sources of PAH compounds in the Gy?r atmosphere were fossil fuel combustion and vehicle emissions.     

Comparison of Different Genotoxic Tests for Biological Monitoring of Coke Oven Workers. Preliminary Results

Chemical by-products of coke production are classified by IARC as carcinogenic in humans. Polycylic aromatic hydrocarbons (PAH) are the main compounds involved in carcinogenic and mutagenic activities of coke oven smokes, but many other compounds are present in emissions and could be involved in these activities. PAH analysis of the atmosphere indicated external contamination, but is not sufficient to evaluate the risk for exposed workers. The aim of this study was to evaluate relationship between atmospheric analysis of PAH and genotoxic markers in coke oven workers'white cells compared to controls. One hundred fifty-five exposed workers'samples were analyzed. They were selected in 5 coke production sites using a complete questionnaire allowing one to exclude all confounding factors. Two equal groups of smokers and nonsmokers were analysed. Analysis of chromosomal aberrations (CA), sister chromatid exchange (SCE), micronucleus (MN) and DNA-adduct formation using ³²P-postlabelling were performed on leucocytes. Each worker was equiped with an individual pump during the shift, for analysis of 16 PAH.

All markers were strongly modified by smoking habits. In smokers, CA, SCE and MN were not influenced by exposure to PAH. The number of DNA-adducts was increased with PAH concentration. In non smokers, we have observed an increaseof breaks / cells and of the percentage of cells with aberrations. Number of MN and SCE were unchanged. The number and the amount of DNA-adducts were strongly increased in exposed workers. DNA-adducts appear to be the best marker for genotoxic risk assessment.     

Characterization of Gaseous and Particulate Polycyclic Aromatic Hydrocarbons in Ambient Air of Delhi,India

Three seasonal sampling campaigns were undertaken at an urban site of Delhi for collection of PAHs in particulate and gas phase. Sampling was done by using modified Respirable Dust (PM ≤10μm) sampler attached with polyurethane foam (PUF) plugs and compared with conventional Respirable Dust (PM ≤10 μm) sampler. Total 16 EPA PAH (gaseous + particulate) were determined by Gas Chromatograph-Mass Spectrophotometer (GC-MS). The 3-ring PAH constitutes approximately 90% of the gaseous PAHs with phenanthrene, fluoranthene, acenapthylene, and acenaphthene being the most abundant gaseous PAHs. PAHs with 4- to 6- rings accounted for 92%, 87% and 78% in samples collected during winter, summer and monsoon season respectively. Gaseous PAHs, particulate PAHs and total PAHs were higher during winter as compared to summer and monsoon seasons. The contribution of particulate PAHs were 1.4, 2.1, and 2.5 times higher in winter, summer and monsoon, respectively than of gaseous PAHs. Indeno[123-cd]pyrene, benzo[ghi]perylene, dibenzo[ah]anthracene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene and chrysene were found to be the most abundant PAH compounds in the particulate PAHs during all the seasons. The result from application of diagnostic ratio suggests that the higher particulate PAHs emissions were predominantly associated with vehicular emissions along with emissions from biomass burning during winter season.     

黄浦江上游太浦河水源水体中全氟化合物赋存特征及风险评价

全氟化合物(PFCs)在水体环境中的风险已引起人们的广泛关注.采用固相萃取、超高效液相色谱串联质谱分析13种PFCs在太浦河水体中的分布特征.结果表明,太浦河水体中检出10种PFCs,总浓度为7.43～120.46 ng/L,PFOA是最主要检出的PFCs种类,最大浓度为42.94 ng/L,检出率为100％,占总PF...     

BIOAVAILABILITY AND BIOACCUMULATION OF PAH IN AMPHIPODS EXPOSED TO REFERENCE AND HARBOR SEDIMENTS

The amphipods Corophium volutator collected from inter-tidal mud flats away from urbanization display the presence of phenanthrene, while larger molecular weight PAHs were only detected in sediments. The latter compounds were abundant in sieved surface sediments collected from Halifax Harbor receiving combined road runoff and sewage effluents and a smaller fraction of the contaminants were bioavailable to amphipods. In laboratory exposures, the kinetics of contaminants uptake by amphipods displayed the steepest increase in concentration the first day of exposure, continued to increase and then decreased, reaching a steady state within a week. The depuration of PAH was more than ten times slower than observed for maximum uptake. Our study indicated the important role played by feeding in the bioavailability and toxicity of sediments. The PAH fingerprint associated with the grain size of particles needs pursuing to better delineate the exposure pathway of PAH to sediment dwelling organisms.     

DDBAC与取代芳烃对发光菌联合毒性作用

表面活性剂和芳烃化合物的大量生产与使用干扰了自然生态系统的物理、化学和生物过程。以发光菌作为指示生物测定了阳离子表面活性剂十二烷基二甲基苄基氯化胺(DDBAC)与苯酚、甲苯和硝基苯对发光菌的单一毒性,以及等摩尔浓度配比下DDBAC与3种取代芳烃二元与多元混合物的联合毒性效应。采用毒性单位(TU)、相加指数(AI)、相似性参数(λ)和混合毒性指数(MTI)4种联合毒性评价方法,对混合体系联合毒性作用类型进行了研究,结果显示,4种不同的评价方法对研究体系联合效应评价结果具有较好的一致性,且不同组分的混合毒性均呈现出较强的协同作用,即DDBAC与取代芳烃共同存在时将会增加该类物质的环境风险性。考察评价方法的有效度,以混合毒性指数法参数值较大,判定灵敏度较高,为该研究体系的推荐评价方法。同时根据发光菌发光原理、结合DDBAC的分子结构特征和芳烃类化合物取代基的不同,对联合毒性作用机理进行初步的探讨。     

The Contribution of Margarine to Cancer Risk from Polycyclic Aromatic Hydrocarbons in the New Zealand Diet

Sixteen samples of New Zealand table margarines were analysed for 16 EPA priority pollutant polycyclic aromatic hydrocarbons (PAH) using gas chromatography-mass spectrometry. All samples contained measurable amounts of PAH and six samples contained more than 10 μg/kg total PAH. The estimated exposure to eight potentially carcinogenic PAH from margarine was 0.002-0.7 μg/day for males and 0.001-0.4 μg/day for females. Based on New Zealand food consumption data and United Kingdom analytical results for eight potentially carcinogenic PAH, the mean daily intake of dietary PAH for New Zealanders is estimated at 1.2 μg/day. The lifetime cancer risk from total ingested PAH is estimated to be 7.5 in 10,000 (7.5 x 10^?4). Margarine is calculated to contribute 2% of this risk based on benzo(a)pyrene levels.     

Elimination of 1-Hydroxypyrene in the Urine of Workers from Different Workplaces as an Indicator of Occupational PAH Exposure

The exposure to PAH of 327 workers occupied at 12 different workplaces has been investigated. Beside conventional ambient monitoring 1-hydroxypyrene was determined in the urine of the employees. Our investigations show that at certain workplaces the internal exposure to PAH of the employees is inadmissibly high although the PAH air concentrations determined at most of the workplaces were below the current threshold limits. Workers from different work places have different 1-hydroxypyrene concentrations in urine. Even employees working at work places with comperable PAH concentrations in air eliminate different 1-hydroxypyrene concentrations in urine. Our results indicate that the determination of PAH in air is not sufficient for health surveillance. To ensure health surveillance a biological monitoring is necessary.     

The Catalytic Total Oxidation of Polycyclic Aromatic Hydrocarbons

Polycyclic Aromatic Hydrocarbons (PAHs) are a group of Volatile Organic Compounds (VOCs), which have serious health problems associated with their emission into the atmosphere. Catalytic oxidation is an effective abatement process to control PAH emissions, and the types of catalysts investigated have been reviewed. The majority of studies have used naphthalene as a model PAH, and in particular, catalysts containing palladium and platinum have demonstrated high activity for total oxidation. Catalysts based on the precious metals include those supported on high surface area supports, which have also been modified by adding further components, and metal exchanged zeolites. Metal oxide catalysts have also been employed and the most active for total oxidation are ceria-based. Studies of PAH total oxidation have largely been reported only in the last 10 years, and there still remains wide scope to develop improved catalysts and understand their catalytic mechanisms.     

Aggregating Data for Computational Toxicology Applications: The U.S. Environmental Protection Agency (EPA) Aggregated Computational Toxicology Resource (ACToR) System

Computational toxicology combines data from high-throughput test methods, chemical structure analyses and other biological domains (e.g., genes, proteins, cells, tissues) with the goals of predicting and understanding the underlying mechanistic causes of chemical toxicity and for predicting toxicity of new chemicals and products. A key feature of such approaches is their reliance on knowledge extracted from large collections of data and data sets in computable formats. The U.S. Environmental Protection Agency (EPA) has developed a large data resource called ACToR (Aggregated Computational Toxicology Resource) to support these data-intensive efforts. ACToR comprises four main repositories: core ACToR (chemical identifiers and structures, and summary data on hazard, exposure, use, and other domains), ToxRefDB (Toxicity Reference Database, a compilation of detailed in vivo toxicity data from guideline studies), ExpoCastDB (detailed human exposure data from observational studies of selected chemicals), and ToxCastDB (data from high-throughput screening programs, including links to underlying biological information related to genes and pathways). The EPA DSSTox (Distributed Structure-Searchable Toxicity) program provides expert-reviewed chemical structures and associated information for these and other high-interest public inventories. Overall, the ACToR system contains information on about 400,000 chemicals from 1100 different sources. The entire system is built using open source tools and is freely available to download. This review describes the organization of the data repository and provides selected examples of use cases.     

Modification of the Versatile Aerosol Concentration Enrichment System (VACES) for conducting inhalation exposures to semi-volatile vapor phase pollutants

A novel sampling system was developed to provide concentrated vapor phase only semi-volatile organic species for in-vivo exposure studies. The system consists of two units: particles (including their semi-volatile component) are first concentrated by means of the Versatile Aerosol Concentration Enrichment System (VACES), and subsequently drawn through a heating section, in which semi-volatile particle-bound components partition to the gas phase, while non-volatile particles are removed by a quartz filter placed after the heater. The vapors are then cooled to ambient temperatures, without producing nano-particles by nucleation, and can be readily used for exposure studies. Laboratory tests were carried out at various heater temperatures using ammonium sulfate, adipic acid and glutaric acid to investigate the occurrence of nucleation in the cooling section. Subsequently the system was tested in the field with concentrated particle and vapor samples taken upstream of the heater, immediately downstream of the filter, and after the cooling section. Chemical analysis of particle and vapor phases upstream and downstream of the system was conducted for selected polycyclic aromatic hydrocarbons (PAHs), and showed very good PAH recovery. These tests indicate that the modified VACES-heater-filter (VHF) system can provide concentrated PM (including their semi-volatile compounds) and PM-bound semi-volatile species purely in the vapor phase for inhalation exposure studies separately, a feature that makes this system an attractive approach for toxicity studies, particularly in light of the increasing interest in health effects of exposures to multi-pollutant atmospheres.     

Selenium's importance in regulatory issues regarding mercury

Current seafood safety and health risk assessment criteria use mercury concentrations as their sole basis. This unfortunate limitation omits consideration of selenium, an essential trace element that appears to be the primary molecular target of mercury toxicity. Although selenium has been recognized for decades as a means of counteracting mercury toxicity, its effects have often been overlooked or misunderstood. Experimental animal studies have demonstrated that increasing concentrations of selenium throughout the normal dietary range increasingly counteracts methylmercury toxicity. Dietary concentrations of selenium that are slightly less than the average amount present in ocean fish have been shown to completely prevent the onset of toxic symptoms of mercury toxicity, while animals fed lesser amounts of selenium rapidly sickened and died. Dietary selenium from a variety of sources including ocean fish such as tuna, swordfish, menhaden, and rockfish has been shown to counteract mercury toxicity. Since ocean fish are among the richest sources of dietary selenium, it is important to include selenium concentration measurements in future mercury risk assessments and seafood safety criteria. Mercury:selenium molar ratios in blood provide far more consistent and physiologically meaningful risk assessments. Comprehensive seafood safety criteria such as the Selenium Health Benefit Value enable clear differentiation between seafoods that are safe and those that are hazardous for human consumption. Use of parameters that integrate mercury–selenium relationships also make it easy to understand the differences between the findings of maternal mercury exposure studies that have been performed in New Zealand, the Faroes, the Seychelles, and the United Kingdom. Development of criteria for evaluating mercury–selenium interactions will enhance environmental protection and improve public safety.