Evaluation of matrix solid-phase dispersion extraction for the determination of polycyclic aromatic hydrocarbons in household dust with the aid of experimental design and response surface methodology

Polycyclic aromatic hydrocarbons in indoor mosques dust in Saudi Arabia: Levels, source apportionment, human health and carcinogenic risk assessment for congregators

Mosques are important places for Muslims where they perform their prayers. The congregators are exposed to hazardous pollutants such as polycyclic aromatic hydrocarbons (PAHs) associated with dust. However, studies on PAHs exposure in religious places are scarce. Air-condition filter (ACF) dust can correspond to air quality to a certain extent, since dust particles derived from indoor and outdoor places stick to it. Therefore, the present study aimed to evaluate the 16 EPA PAHs in ACF dust from mosques to determine their levels, profiles, sources and risks. Average Σ16 PAHs concentrations were 1039, 1527, 2284 and 5208 ng/g in AC filter dust from mosques in residential (RM), suburban (SM), urban (UM) and car repair workshop (CRWM), respectively, and the differences were statistically significant (p < 0.001). Based on the molecular diagnostic PAH ratios, PAHs in mosques dust is emitted from local incomplete fuel combustion, as well as complete fossil fuels combustion sources (pyrogenic), petroleum spills, crude and fuel oil, traffic emissions, and other possible sources of industrial emissions in different functional areas. The incremental lifetime cancer risks (ILCRs) values for children and adults across the different types of mosques follow the order: CRWM > UM > SM > RM. ILCRs values for both children and adults were found in order: dermal contact > ingestion > inhalation. The cancer risk levels via ingestion for children were relatively higher than the adults. The values of cancer risk for children and adults via dermal contact and ingestion (except in RM) were categorized in the 'potentially high risk' category (> 10-4). The mean values of total cancer risks (CR) for children (5.74 × 10-3) and adults (5.07 × 10-3) in mosques also exceeded the accepted threat value (>10-4). Finally, it is recommended that regular and frequent monitoring of PAHs should be carried out in mosques to improve the quality and maintain the health of congregators around the globe.

Polycyclic Aromatic Hydrocarbons in Indoor Dust in Croatia: Levels, Sources, and Human Health Risks

Compounds that contribute to indoor pollution are regularly investigated due to the fact that people spend most of their time indoors. Worldwide investigations have shown that polycyclic aromatic hydrocarbons (PAHs) are present in indoor dust, but to the best of our knowledge, this paper reports for the first time the presence of PAHs in Croatian households. Eleven PAHs were analysed in house dust samples collected in the city of Zagreb and surroundings (N = 66). Their possible indoor sources and the associated health risks were assessed. Total mass fraction of detected PAHs ranged from 92.9 ng g^-1 to 1504.1 ng g^-1 (median 466.8 ng g^-1), whereby four-ring compounds, Flu and Pyr, contributed the most. DahA was the only compound that did not show statistically significantly positive correlation with other analysed PAHs, indicating that it originated from different sources. Based on diagnostic ratios and principal component analysis (PCA), mixed sources contributed to PAHs levels present in Croatian households. Although our results indicate that Croatian house dusts are weakly polluted with PAHs, total ILCR values calculated for children and adults revealed that people exposed to the highest mass fractions of PAHs measured in this area are at elevated cancer risk.

Research Progress of Polycyclic Aromatic Hydrocarbons Pretreatment Methods and Application of Computer Simulation Technology for Prediction and Degradation of Electrochemical Concentration Detection

Polycyclic aromatic hydrocarbons (PAHs) are a class of organic compounds that are composed of aromatic rings containing only carbon and hydrogen atoms. They are one of the widespread environmental pollutants in the world. In recent years, many scholars have focused on the inhibition, formation mechanism, content of active components, and biodegradation effect of polycyclic aromatic hydrocarbons. They summarized the research progress of pretreatment methods for detection, but rarely discussed the experimental dataset for comprehensive analysis of pollution sources and the impact of different pretreatment technologies on the extraction of different substrates. What is more, computer simulation has not been mentioned. In this study, the pollution sources of polycyclic aromatic hydrocarbons (PAHs) are reviewed, and the related applications of various pretreatment methods such as gel permeation chromatography (GPC) are summarized. Finally, the computer simulation of the response surface method is introduced. The concentration of polycyclic aromatic hydrocarbons is tested or predicted by combining the neural network with the alternating trilinear decomposition (ATLD) algorithm, artificial population algorithm (ABC), and hierarchical genetic algorithm (HGA). Its future development trend is discussed and prospected, which provides a reference for solving the pollution problem. We look forward to providing help for the follow-up research of scholars in this field.

A case study on the occurrence of polycyclic aromatic hydrocarbons in indoor dust of Serbian households: Distribution, source apportionment and health risk assessment

This study was conducted in order to obtain the first insight into the occurrence, potential sources, and health risks of polycyclic aromatic hydrocarbons (PAHs) in indoor dust. Samples (n = 47) were collected from households in four settlements in the northern Serbian province of Vojvodina. Total concentrations of 16 EPA priority PAHs in the dust samples varied from 140 to 8265 μg kg^-1. Mean and median values for all samples were 1825 and 1404 μg kg^-1, respectively. According to the international guidelines for indoor environment, PAH content can be regarded as normal (<500 μg kg^-1) for ∼6% of the samples, high (500-5000 μg kg^-1) for ∼87% of the samples, and very high (5000-50000 μg kg¹) for ∼6% of the samples. In all settlements, PAHs with 4 rings were the most prevalent (accounting for 40-53% of the total PAHs). They were followed by 3-ringed PAHs (29-40%), which indicates rather uniform PAH profiles in the analyzed dust. Based on diagnostic ratios, principal component analysis (PCA), and positive matrix factorization (PMF), pyrogenic sources, such as vehicle emissions and wood combustion were the dominant sources of PAHs in analyzed samples. Health risk assessment, which included incidental ingesting, inhaling and skin contact with PAHs in the analyzed dust, was evaluated by using the incremental lifetime cancer risk (ILCR) model. Median total ILCR was 3.88E-04 for children, and 3.73E-04 for adults. Results revealed that major contribution to quite high total ILCRs was brought by dermal contact and ingestion. Total cancer risk for indoor dust indicated that 85% of the studied locations exceeded 10-4. This implies risk of high concern, with potential adverse health effects. The results are valuable for future observation of PAHs in indoor environment. They are also useful for regional authorities who can use them to create policies which control sources of pollution.

Toxic organic pollutants in Greek house dust: Implications for human exposure and health risk

Organic contaminants often documented in house dust include mainly chemicals released from construction materials and consumer products and compounds emitted from indoor combustion activities. The occurrence of major chemical classes of toxic organic pollutants, included polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs) and nitrated polycyclic aromatic hydrocarbons (NPAHs), was for the first time investigated in house dust in Greece. The mean concentrations of ∑₁₆PAHs, ∑₂₀PBDEs, ∑₇NPAHs and∑₁₅PCBs in house dust were 4650 ng g^-1, 564 ng g^-1, 7.52 ng g^-1, and 6.29 ng g^-1, respectively. Exposure to dust organic contaminants via ingestion, inhalation and dermal absorption was estimated for two age classes (adults and children) and carcinogenic and non-carcinogenic risks were assessed. The hazard index (HI) for adults and children for PBDEs, PCBs, PAHs and NPAHs in all samples was less than 1 suggesting a very low level of concern for all human age group due to exposure to those chemicals. Total carcinogenic risk via the three exposure pathways (ingestion, inhalation and dermal contact) was within the safe range of 10^-6 to 10^-4.

Determination of multi-class polyaromatic compounds in sediments by a simple modified matrix solid phase dispersive extraction

A simple, efficient matrix solid phase dispersive extraction (MSPD) method was optimised to analyse simultaneously polycyclic aromatic hydrocarbons (PAHs) and polychlorobiphenyls (PCBs) from sediments, and was compared to microwave-assisted extraction (MAE). New dispersing agents were tested to improve MSPD extraction. 3-chloropropyl-bonded silica particles, in addition to Florisil, increased significantly the polyaromatics desorption capacity. A compromise was found for eluting both families of compounds from sediments, using a small volume of hexane/acetone. Low procedural detection limits could be reached (0.06-0.22 ng g^-1 and 0.3-1.1 ng g^-1 for PAHs and PCBs, respectively). Mean total extraction recoveries were good for PAHs (>67%, depending on the sediment) and for PCBs (>89%), with good precision (6-9% and 4-10% inter-day precision for PAHs and PCBs, respectively). Higher recoveries for PCBs could be reached in comparison with formerly developed sonication or Soxhlet extraction methods, but also with MAE. MSPD offered significant decrease of sample amount, of solvent consumption and allowed more efficient cleaning of the sediment matrix, leading to less matrix effects compared to MAE, removing lots of interfering compounds without additional purification step. The robustness of the MSPD methodology could be demonstrated extracting quantitatively sediments from different sources and with various mineralogical characteristics.

Health risks associated with the polycyclic aromatic hydrocarbons in indoor dust collected from houses in Kuwait

Polycyclic aromatic hydrocarbons (PAHs) are a byproduct of combustion processes. They are common pollutants in oil-producing countries because fossil fuel processing generates PAHs that associate with dust. Airborne particles containing PAHs are transported into houses during dust storms, which are common in the arid oil-producing countries, and consequently the children and adults in the household are exposed to PAHs in indoor house dust. The goal of this study was to present a systematic survey of PAHs in indoor house dust in Kuwait. The PAHs concentrations and composition of indoor house dust was determined, along with their probable source and the potential carcinogenic risks. Total PAHs concentrations (ƩPAH) were, on average (±standard deviation) 1112 ± 347 μg/kg and ranged from 450 to 2242 μg/kg. Heavier congeners (4-6 ring PAHs) represented 61% of the ƩPAH. Petroleum combustion and traffic emissions were the major source of PAHs, based on the isomeric ratios of PAHs in indoor house dust. The incremental lifetime cancer risks (ILCRs) of exposure to PAHs in indoor house dust was 2.23 × 10^-3 (95% CI: 1.99 × 10^-3 - 2.48 × 10^-3) for children and 2.15 × 10^-3 (95% CI: 1.94 × 10^-3 - 2.37 × 10^-3) for adults, exceeding the US EPA safe limit of 1 × 10^-6. Therefore, exposure to PAHs present in indoor house dust increases the cancer risk for children and adults in Kuwait.

A pilot study on semivolatile organic compounds in senior care facilities: Implications for older adult exposures

The occurrence of five groups of semivolatile organic compounds (SVOCs) (total of ∼120 distinct chemicals) was investigated in senior care facilities in the United States and in Portugal. Indoor settled dust samples were collected from fourteen facilities, and the concentrations of organophosphate esters (OPEs), brominated flame retardants (BFRs), polycyclic aromatic hydrocarbons (PAHs), organochlorine pesticides (OCPs), and polychlorinated biphenyls (PCBs) were measured in these samples. Overall, OPEs, PAHs, and BFRs were the most abundant, and OCPs and PCBs were the least abundant SVOC groups in dust collected from both U.S. and Portuguese facilities. ∑OPE, ∑PAH, and ∑BFR concentrations were significantly higher in U.S. facilities than those in Portuguese facilities (P < 0.001), while ∑OCP and ∑PCB concentrations were not different between the two countries (P < 0.05). The samples were collected from three different microenvironments, including bedrooms, living rooms, and corridors. ∑OPE, ∑PAH, and ∑BFR concentrations were up to five times higher in corridors compared to bedrooms and living rooms. ∑OCP and ∑PCB concentrations were overall higher in bedrooms and in living rooms and lower in corridors.

Spatiotemporal analysis and human exposure assessment on polycyclic aromatic hydrocarbons in indoor air, settled house dust, and diet: A review

This review summarizes the published literature on the presence of polycyclic aromatic hydrocarbons (PAH) in indoor air, settled house dust, and food, and highlights geographical and temporal trends in indoor PAH contamination. In both indoor air and dust, ΣPAH concentrations in North America have decreased over the past 30 years with a halving time of 6.7±1.9years in indoor air and 5.0±2.3 years in indoor dust. In contrast, indoor PAH concentrations in Asia have remained steady. Concentrations of ΣPAH in indoor air are significantly (p<0.01) higher in Asia than North America. In studies recording both vapor and particulate phases, the global average concentration in indoor air of ΣPAH excluding naphthalene is between 7 and 14,300 ng/m(3). Over a similar period, the average ΣPAH concentration in house dust ranges between 127 to 115,817ng/g. Indoor/outdoor ratios of atmospheric concentrations of ΣPAH have declined globally with a half-life of 6.3±2.3 years. While indoor/outdoor ratios for benzo[a]pyrene toxicity equivalents (BaPeq) declined in North America with a half-life of 12.2±3.2 years, no significant decline was observed when data from all regions were considered. Comparison of the global database, revealed that I/O ratios for ΣPAH (average=4.3±1.3), exceeded significantly those of BaPeq (average=1.7±0.4) in the same samples. The significant decline in global I/O ratios suggests that indoor sources of PAH have been controlled more effectively than outdoor sources. Moreover, the significantly higher I/O ratios for ΣPAH compared to BaPeq, imply that indoor sources of PAH emit proportionally more of the less carcinogenic PAH than outdoor sources. Dietary exposure to PAH ranges from 137 to 55,000 ng/day. Definitive spatiotemporal trends in dietary exposure were precluded due to relatively small number of relevant studies. However, although reported in only one study, PAH concentrations in Chinese diets exceeded those in diet from other parts of the world, a pattern consistent with the spatial trends observed for concentrations of PAH in indoor air. Evaluation of human exposure to ΣPAH via inhalation, dust and diet ingestion, suggests that while intake via diet and inhalation exceeds that via dust ingestion; all three pathways contribute and merit continued assessment.