Pollution Health Research Articles

Impact of Forest and Land Fires on Environmental Pollution and Public Health in Sungai Raya Sub-District, Kubu Raya District

Forest and land fires in Sungai Raya District, Kubu Raya Regency, severely impact environmental pollution and public health. This condition causes quite significant ecological and social losses. First, the smoke produced from these fires contains various dangerous substances, such as carbon monoxide, dust particles, and toxic chemicals. Continuous exposure to these substances can cause respiratory problems, respiratory tract diseases, and other health problems in local communities. Apart from that, forest fires also result in the loss of natural habitat for various species of flora and fauna. Disrupted ecosystems can cause biodiversity loss and affect local food chains. Recovery of fire-affected ecosystems takes a long time, and some species may experience local extinction due to habitat loss. Furthermore, preventing and responding to forest fires requires significant resources in terms of personnel and equipment. Funds allocated for firefighting can disrupt local government budgets that should be used for infrastructure development and community welfare programs. Therefore, forest fires harm the environment and health and impose an economic burden on the people of Sungai Raya District. Efforts to prevent forest and land fires and educate the public regarding the risks of prevention are essential to overcome these negative impacts. Sustainable measures such as law enforcement against illegal forest burning, sustainable land management, and increasing public awareness of the importance of preserving the environment can help reduce fire risks and protect public health.

Participatory assessment of pollution and health risk in artisanal and small-scale gold mining communities in Colombia

The predominantly Afro-descendant communities of Yolombó and La Toma depend on the region's rich natural resources through livelihoods such as farming, fishing, and artisanal and small-scale gold mining (ASGM). Previous studies of the region have identified elevated levels of mercury in several surface and groundwater sites. Furthermore, recent regional studies have identified human health risks associated with mercury exposure through hazard quotient (HQ) modeling and global sensitivity and uncertainty analysis (GSUA). However, there has yet to be a comprehensive analysis of water pollution involving different metals and metalloids potentially present in ASGM-influenced areas to estimate the associated environmental and human health impacts. In this study, we employed a participatory methodology to identify sources of exposure in Colombian ASGM communities through surveys, consumption diaries, and interviews. We then screened for relevant metals and metalloids through groundwater analysis using inductively coupled plasma optical emission spectroscopy (ICP-OES) and cold vapor atomic absorption spectrometry (CV-AAS). Furthermore, we calculated water pollution indices, including heavy metal pollution index (HPI), degree of contamination (Cd), heavy metal toxicity load (HMTL) and heavy metal evaluation index (HEI). Finally, we quantified human health risks related to groundwater consumption through the HQ and hazard index (HI). Although the groundwater assessed in this study generally meets United States and Colombian regulatory standards, heightened Fe, Mn, and Al levels were observed. The pollution indices generally agreed that three of the sites tested showed medium to high pollution levels. The HI showed that the combined effect of all metals tested did not substantiate risk for most participants. However, the HI of one participant, a child, exceeded the 1.00 threshold. Furthermore, the presence of Pb, despite meeting regulatory limits, necessitates further scrutiny due to its substantial impact on pollution and human health hazard indices.

Pollution status and health risk assessment of heavy metals in the soil of Sahibzada Ajit Singh (SAS) Nagar district of Punjab, India and its source apportionment

The threat of heavy metals in soil due to rapid urbanization, intensive agricultural practices, vehicular emission, and industry-related activities is increasing day by day, causing high risk to environmental health. The present study assessed the heavy metal pollution (Cr, Co, Ni, Co, Zn, As, Cd, and Pb) in the soil of Sahibzada Ajit Singh Nagar District, Punjab, India, through the index of geoaccumulation (Igeo), contamination factors (CF), degree of contamination (DC), pollution load index (PLI), ecological risk factor (Er) and potential ecological risk indices (PRI). The results showed the concentration of heavy metals in the soil in the order of Pb > Zn > Ni > Cr > Cu > As > Co > Cd. The pollution risk assessment indices: Igeo, CF, and Er indicated that most soil samples were moderately contaminated with Pb. The village Majra showed considerable contamination as evidenced by the Cd. The multivariate statistical analysis revealed the anthropogenic sources (agricultural practices and discharges from micro, small and medium enterprises (MSME) industries) to be the possible sources of Cr, Co, Ni, Cu, Zn, and Pb. The health risk assessment studies indicated that carcinogenic risks were higher for children than the adults. The cancer risk (CR) for all heavy metals in decreasing order is As > Cr > Pb > Ni > Cd. Likewise, the non-carcinogenic risks calculated as HQ followed the order of Pb > As > Cr > Cd > Ni > Cu > Co > Zn. The significant disparities in heavy metal concentrations underscore the necessity of establishing appropriate baseline levels for toxic trace metals in soils.

Objective and subjective measures of air pollution and self-rated health: the evidence from Chile.

The literature exploring individual differences in self-rated health has grown fast in recent years. Self-rated health (SRH) is a good indicator of general health status. This empirical study explores the association between outdoor air pollution and SRH in Chile. This type of analysis is infrequent in Latin America. We used objective and subjective air pollution measures. The first corresponds to PM2.5, and the latter to the perception of a high level of air pollution. Drawing on data from two independent and repeated nationwide surveys over the period 2006-2017 at the individual level in Chile, we performed repeated cross-sectional analyses for each year of survey application. Ordered Logit (OL) and Logit (L) multivariate models were used to investigate the association between SRH and air pollution measures, considering other socioeconomic and demographic covariates. We found that the higher isthe level of air pollution, the lower the SRH in Chile, regardless of whether air pollution is physically measured or perceived by respondents. The results were consistent over the years in the sign and significance of regression coefficients using two surveys and two forms of the outcome variable. Our findings add evidence that air pollution is a relevant determinant of SRH. In addition, they show that subjective measures of air pollution can be as reliable as physical measures in the analysis of the association between air pollution and human health.

Analysis, distribution, and health evaluation of 8 biogenic amines in Chinese mackerel products by CoFe2O4/MEG solid phase extraction-HPLC

A CoFe2O4/MEG solid-phase extraction combined with high performance liquid chromatography was used for determination of 8 biogenic amines (Bas) in canned Spanish mackerel products. A new comprehensive evaluation system, including dietary exposure, food safety index, chemical quality index and biogenic amine index, was used for investigating the pollution distribution, exposure and health assessment of BAs in four sea areas/provinces of China. The pollution levels in the Yellow Sea-Jiangsu, Bohai Sea-Shandong, Yellow and Bohai Sea-Liaoning regions were equivalent, with ∑8BAs equalling 34.7–36.5 mg/kg, while in the South China Sea-Guangdong region ∑8BAs was lowest at 18.9 mg/kg. The concentration range of ∑8BAs and ∑4BAs were ND (not detected)-113 mg/kg and ND-80.8 mg/kg, respectively. All results showed that the main components of BAs were putrescine, histamine, and spermine, with detection rates ranging from 23.1% to 42.3%. The dietary exposure level range of 8 BAs was 85.8–266 μg∙kg−1∙d−1, IFSc was 0.00800–0.0248, CQI values range in the four regions was 1.21–3.93, with a mean CQI of 1.98. The total value of BAI ranges ND-0.840 mg/kg, with a mean BAI of 20.3 mg/kg. Statistical analysis showed that the overall health risk of BAs exhibits different trends in terms of gender, age, and region.

Spatial and temporal distribution characteristics and risk assessment of heavy metals in groundwater of Pingshuo mining area.

Groundwater pollution in the Pingshuo mining area is strongly associated with mining activities, with heavy metals (HMs) representing predominant pollutants. To obtain accurate information about the pollution status and health risks of groundwater, 189 groups of samples were collected from four types of groundwater, during three periods of the year, and analyzed for HMs. The results showed that the concentration of HMs in groundwater was higher near the open pit, waste slag pile, riverfront area, and human settlements. Except for Ordovician groundwater, excessive HMs were found in all investigated groundwater of the mining area, as compared with the standard thresholds. Fe exceeded the threshold in 13-75% of the groundwater samples. Three sources of HMs were identified and quantified by Pearson's correlation analysis and the PMF model, including coal mining activities (68.22%), industrial, agricultural, and residential chemicals residue and leakage (16.91%), and natural sources (14.87%). The Nemerow pollution index revealed that 7.58% and 100% of Quaternary groundwater and mine water samples were polluted. The health risk index for HMs in groundwater showed that the non-carcinogenic health risk ranged from 0.18 to 0.42 for adults, indicating an acceptable level. Additionally, high carcinogenic risks were identified in Quaternary groundwater (95.45%), coal series groundwater (91.67%), and Ordovician groundwater (26.67%). Both carcinogenic and non-carcinogenic risks were greater for children than adults, highlighting their increased vulnerability to HMs in groundwater. This study provides a scientific foundation for managing groundwater quality and ensuring drinking water safety in mining areas.

Peptide-Decorated Microneedles for the Detection of Microplastics.

The escalating utilization of plastics in daily life has resulted in pervasive environmental pollution and consequent health hazards. The challenge of detecting and capturing microplastics, which are imperceptible to the naked eye, is exacerbated by their diminutive size, hydrophobic surface properties, and capacity to absorb organic compounds. This study focuses on the application of peptides, constituted of specific amino acid sequences, and microneedles for the rapid and selective identification of microplastics. Peptides, due to their smaller size and greater environmental stability compared with antibodies, emerge as a potent solution to overcome the limitations inherent in existing detection methodologies. To immobilize peptides onto microneedles, this study employed microneedles embedded with gold nanorods, augmenting them with sulfhydryl (SH) groups at the peptides' termini. The sensor developed through this methodology exhibited efficient peptide binding to the microneedle tips, thereby facilitating the capture of microplastics. Raman spectroscopy was employed for the detection of microplastics, with the results demonstrating successful attachment to the microneedles. This novel approach not only facilitates localized analysis but also presents a viable strategy for the detection of microplastics across diverse environmental settings.

Flavonoids as Insecticides in Crop Protection-A Review of Current Research and Future Prospects.

Pesticide overuse in agricultural systems has resulted in the development of pest resistance, the impoverishment of soil microbiota, water pollution, and several human health issues. Nonetheless, farmers still depend heavily on these agrochemicals for economically viable production, given the high frequency at which crops are affected by pests. Phytopathogenic insects are considered the most destructive pests on crops. Botanical pesticides have gained attention as potential biopesticides and complements to traditional pesticides, owing to their biodegradability and low toxicity. Plant-based extracts are abundant in a wide variety of bioactive compounds, such as flavonoids, a class of polyphenols that have been extensively studied for this purpose because of their involvement in plant defense responses. The present review offers a comprehensive review of current research on the potential of flavonoids as insecticides for crop protection, addressing the modes and possible mechanisms of action underlying their bioactivity. The structure-activity relationship is also discussed. It also addresses challenges associated with their application in pest and disease management and suggests alternatives to overcome these issues.

Modeling Urban-Rural health disparities using a Taxi-Based mobile atmospheric monitoring system

The disparities of pollutant exposures and health burdens exists among regions. To capture the spatio-temporal variability of PM2.5 and analyze the inequity between urban and rural areas, this study developed a health impact assessment (HIA) model, which incorporates hyper-localized roadside PM2.5 concentration collected by a taxi-based mobile monitoring system. High-resolution pollutant concentrations, health risks, and PM2.5-related deaths were mapped to illustrate the spatio-temporal patterns among regions. The results showed that the average PM2.5 concentrations in some rural counties were higher than urban areas. 7.85%, 3.72%, 8.74%, and 0.97% of individuals were exposed to environment higher than the maximum concentration of central districts in winter, spring, summer, and autumn, respectively. The application of refined HIA model was discussed and grid cells with high risks of all-cause mortality, cardiovascular disease, respiratory disease, and lung cancer were identified. Establishing the comprehensive pollutant monitoring system facilitates targeted interventions and realization of health equity.

Dark under the Lamp: Neglected Biological Pollutants in the Environment Are Closely Linked to Lung Cancer.

Environmental pollutants are closely linked to lung cancer. The different types of environmental pollutants can be classified as chemical, physical, and biological. The roles of common chemical and physical pollutants such as PM2.5, smoking, radon, asbestos, and formaldehyde in lung cancer have been extensively studied. Notably, the worldwide COVID-19 pandemic raised awareness of the strong link between biological pollution and human health. Allergens such as house dust mites and pollen, as well as bacteria and viruses, are common biological pollutants. A few biological pollutants have been reported to promote lung cancer via inducing inflammatory cytokines secretion, such as IL-1β, IL-6, and TGF-β, as well as suppressing immunosurveillance by upregulating regulatory T (Treg) cells while dampening the function of CD8+ T cells and dendritic cells. However, the correlation between common biological hazards, such as SARS-CoV-2, human immunodeficiency viruses, Helicobacter pylori, and house dust mites, and lung cancer is not fully elucidated, and the underlying mechanisms are still unclear. Moreover, the majority of studies that have been performed in lung cancer and biological carcinogens were not based on the perspective of biological pollutants, which has challenged the systematicity and coherence in the field of biological pollutants in lung cancer. Here, in addition to reviewing the recent progress made in investigating the roles of allergens, viruses, and bacteria in lung cancer, we summarized the potential mechanisms underlying biological pollutants in lung cancer. Our narrative review can shed light on understanding the significance of biological pollutants in lung cancer, as well as inspire and broaden research ideas on lung cancer etiology.

Construction of 2D/3D black g-C3N4/BiOI S-scheme heterojunction for boosted photothermal-assisted photocatalytic tetracycline degradation in seawater

Utilization of semiconductor photocatalyst to degrade broad-spectrum antibiotics (tetracycline, TC) in seawater to solve environmental pollution and human health problems has become a research hotspot in recent years. In this work, 2D/3D black g-C3N4/BiOI S-scheme heterojunction was constructed by loading 2D black g-C3N4 (CN-B) nanosheets onto 3D spherical bismuth oxyiodide (BiOI) surface by solvothermal method to improve TC degradation efficiency. The TC (30 mg/L) photodegradation efficiency of the optimal 10 % CN-B/BiOI sample was up to 93 % after 60 min visible light irradiation, which was significantly higher than that of pure CN-B and BiOI. Remarkably, the 2D/3D heterojunction formed between CN-B and BiOI can not only effectively improve the light absorption and separation efficiency of carriers, but also the photothermal effect of CN-B increases the reaction temperature, thereby promoting the photothermal-assisted photocatalytic degradation activity. This work provides a promising strategy and systematic method for the design of photocatalytic system for photothermal-assisted degradation antibiotic contaminants in seawater.

Seasonal subsurface water quality variation of physiochemical and bacteriological characteristics in Kamutwa-Kigali, Rwanda

Abstract The study was conducted to assess subsurface water quality on a seasonal basis in dry (January–February and June–August) and rainy (March and October–December) seasons. Samples were collected in the rainy and dry seasons of the year 2022. The results of this study were compared with global drinking water guidelines of the World Health Organization (WHO) to understand its status in terms of threshold levels of pollution and protect public health. Total hardness (TH), pH, alkalinity, electrical conductivity (EC), total dissolved solids (TDS), nitrate, sulfate, heavy metals (Zn, Mn, and Fe), fecal, and total coliforms were examined, and the water quality index (WQI) was calculated to assess the level of water contamination. The results indicated that during the rainy season, all physiochemical parameters gradually increased and the values were well within the permissible limit as prescribed by the WHO. The bacteriological test showed that there were no fecal coliform (FC) and total coliform (TC) in all trials performed, and the calculated WQI showed excellent water quality characteristics, thus proving fit for human consumption.

Identification of groundwater pollution sources and health risk assessment in the Fengshui mining area of Central Shandong, China.

The crux of groundwater protection lies in a profound understanding of the sources of pollutants and their impacts on human health. This study selected 47 groundwater samples from the Fengshui mining area in central Shandong Province, China, employing advanced hydrogeochemical techniques, positive matrix factorization (PMF), and Monte Carlo analysis methods, aimed at unveiling the characteristics, origins, and health risks of water pollutants. The results indicated that the majority of samples exhibited a slightly alkaline nature. Notably, the concentrations of fluoride (F-) and nitrate (NO3-) exceeded China's safety standards in 40.43% and 23.40% of the samples, respectively. Moreover, a water quality index (WQI) below 50 was observed in approximately 68.09% of the sites, suggesting that the water quality in these areas generally met acceptable levels. However, regions with higher WQI values were predominantly located in the northern and southern parts of the mining area. PMF analysis revealed that regional geological and industrial activities were the primary factors affecting water quality, followed by mining discharges, fundamental geological and agricultural processes, and leachate enrichment activities. The health risk assessment highlighted the heightened sensitivity of the youth demographic to fluoride, with a more pronounced non-carcinogenic risk compared to nitrate, affecting about 31.89% of the youth population. Hence, it is imperative for local authorities and relevant departments to take prompt actions to remediate groundwater contamination to minimize public health risks.

Invited Perspective: Increasing Disparities in Air Pollution Health Burdens in the United States-A Concerning Trend for and a Path Forward.

Invited Perspective: Increasing Disparities in Air Pollution Health Burdens in the United States-A Concerning Trend for and a Path Forward.

A study on indoor air pollution and its impact on health in urban field practice area: a community-based study

Background: As per the 2022 World Air Quality Report, India holds the eighth position globally for air pollution, with Karnataka in South India experiencing notably poor air quality, leading to 95 deaths per 100,000 population annually. Indoor air pollution poses substantial health risks, contributing to conditions such as pneumonia, stroke, diabetes, lung cancer, and premature mortality. Methods: This study, conducted from April to July 2023 in the urban area of UHTC, Chandabowdi, aimed to assess indoor air pollution's impact. Using simple and systematic random sampling, 128 household members were surveyed through in-person interviews with ethical clearance. Results: Of 128 participants, 44% reported respiratory symptoms, and 94% practiced unsanitary waste disposal. Ventilation issues affected 32.8%, while 75.8% reported neighborhood pollution. LPG was the primary fuel source for 97.7% of households, indicating significant environmental and health concerns. Conclusions: Urgent action is needed to address indoor air pollution's health impacts. Clean technologies, improved building design, and lifestyle changes are essential to mitigate risks. Continuous monitoring and collective efforts are necessary for a healthier and sustainable future.

Pollution characteristics and health risk assessment of fine particulate matter and its metal elements during Chinese New Year

The Chinese Lunar New Year is a significant festival in China that leads to indoor and outdoor air pollution with distinct characteristics compared to normal times. In this study, indoor and outdoor air samples were collected and analysed to investigate the indoor and outdoor pollution of PM2.5 and its metal elements during the Chinese New Year. The findings reveal that there is a notable positive correlation between indoor and outdoor PM2.5 concentrations during the Chinese New Year, with outdoor concentrations being higher on average. The levels of PM2.5 concentrations indoors and outdoors started to increase on Chinese New Year’s Eve and peaked after the early hours of the Chinese New Year. The total concentrations of six metal elements (Cd, Cr, Ni, Cu, Pb and Zn) in indoor and outdoor PM2.5 during the Chinese New Year in 2022 were 738.73 ± 134.93 mg/kg and 1124.38 ± 553.14 mg/kg, respectively. Principal component analysis suggests that the main sources of indoor metal elements were from outdoor combustion sources and human activities, while outdoor sources were fireworks displays and emissions from coal combustion. Based on the U.S. EPA risk assessment carried out, both indoor and outdoor PM2.5 metal elements could pose a carcinogenic risk to adults.

Global trade-driven transfer of atmospheric polycyclic aromatic hydrocarbon emissions and associated human inhalation exposure risk

Polycyclic aromatic hydrocarbons (PAHs) are of significant public concern because of their toxicity and long-range transport potential. Extensive studies have been conducted to explore the source-receptor relationships of PAHs via atmospheric transport. However, the transfer of trade-driven regional and global PAHs is poorly understood. This study estimated the virtual PAHs emission transfer embodied in global trade from 2004 to 2014 and simulated the impact of international trade on global contamination and associated human inhalation exposure risk of PAHs. Results show that trade-driven PAHs flowed primarily from developed to less-developed regions, particularly in those regions with intensive heavy industries and transportation. As the result, international trade resulted in an increasing risk of lung cancer induced by exposure to PAHs (27.8% in China, 14.7% in India, and 11.3% in Southeast Asia). In contrast, we found decreasing risks of PAHs-induced lung cancer in Western Europe (63.2%) and the United States (45.9%) in 2004. Our findings indicate that final demand and emission intensity are the key driving factors contributing to rising and falling consumption-based PAHs emissions and related health risk respectively. The results could provide a useful reference for global collaboration in the reduction of PAHs pollution and related health risks.

Assessment of Heavy Metal(loid) Pollution and Human Health Risks Associated with a Mineral (Zn, Cu, and Sn Ores) Processing Plant in Yunnan, Southwest China

Understanding the contamination and sources of heavy metal(loid)s (HMs) at historical sites is vital for safeguarding human health and the ecological environment. This study focused on As, Hg, Cd, Cu, Pb, Ni, and Cr concentrations in the residual soil, groundwater, and surface water around a mineral processing plant. The sources of these elements and the human health risks posed by them were evaluated using various indexes. Soil HM concentrations exceeded background values for Yunnan Province, ranked as As > Pb > Cd > Cu > Hg > Ni. The river water met China’s Class II waterbody standard; however, Cd, Cu, Pb, and pH exceeded the maximum permissible sewage discharge concentrations in the accumulated water. The groundwater showed severe HM pollution, meeting China’s Class III water quality standard. The average value of the Nemerow pollution index was consistent with that of the single-factor pollution index in the following order: As > Pb > Cd > Ni > Cu > Hg. Children face heightened risk through the oral ingestion of As, Cd, and Pb, particularly in high-value sampling points in the residue deposit area. The main sources of these pollutants are anthropogenic activities and the soil formation matrix.

Ecological pollution features and health risk exposure to heavy metals via street dust and topsoil from Nkpor and Onitsha in Anambra, Nigeria.

The manuscript presents the investigation results on the pollution and risk of metal mines, and it is considered an important report on environmental pollution near mines in Nigeria, with archival value. The research involved soil sampling and heavy metal analysis for about 12 months in three metal mines. Based on these results, the paper provides information on pollution levels and hazards using well-known methods like pollution and ecological risk indexes. The increasing population in urban communities attracted by various industrial, economic and social activities causes contamination of atmospheric environment that can affect human health. We investigated heavy metal distributions, correlation coefficient among elements, ecological indices and probable health risk assessment in street dust and topsoil from Nkpor and Onitsha urban suburb, Nigeria. The mean concentration of heavy metals in car dust from Onitsha and Nkpor suburb follows thus: Fe > Mn > Cu > As > Pb > Ni > Cr. The decreasing trend of heavy metal in rooftop dust from both area: Fe > Mn > Cu > Pb > As > Ni > Cr whereas metal contents in topsoil were: Fe > Mn > Cu > Pb > Ni > Cr > As for both areas. The degree of pollution indices was characterized by contamination factor (CF), geo-accumulation factor (I-geo), pollution load index (PLI), Nemerow (PN), ecological and potential ecological risk index (ER and PERI) which indicated low pollution in the urban street environment. The results of Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA) showed that the estimated heavy metals displayed sources from atmospheric deposition, natural origin and anthropogenic sources. Risk assessment revealed that ingestion of dust and soil was the significant route for heavy metals exposure to the populace followed by inhalation, then dermal contact. Considering all factors, non-cancer risk was more prominent in children than adults and no significant health hazard could be attributed to both aged groups as of the period of study except for As and Ni that needs constant monitoring to avoid exceeding organ damaging threshold limit of 1 × 10-4.

Pollution Characteristics and Health Risks of Polycyclic Aromatic Compounds (PACs) in Soils of a Coking Plant.

Coke production is an important source of environmental polycyclic aromatic compounds (PACs), including parent polycyclic aromatic hydrocarbons (PAHs) and their derivatives. The focus near coking plants has primarily been on parent-PAH contamination, with less attention given to highly toxic derivatives. In this study, soil samples were collected from both within and outside of a coking plant. The concentrations of parent-PAHs and their derivatives, including methylated-PAHs, oxygenated-PAHs, and nitrated-PAHs, were examined. Spatial interpolation was employed to determine their spatial distribution patterns. Methods for identifying potential sources and conducting incremental lifetime cancer risk analysis were used. This could achieve a comprehensive understanding of the status of PAC pollution and the associated health risks caused by coke production. The concentrations of total PACs inside the plant ranged from 7.4 to 115.8 mg/kg, higher than those outside (in the range of 0.2 to 65.7 mg/kg). The spatial distribution of parent-PAH concentration and their derivatives consistently decreased with increasing distance from the plant. A significant positive correlation (p < 0.05) among parent-PAHs and their derivatives was observed, indicating relatively consistent sources. Based on diagnostic ratios, the potential emission sources of soil PACs could be attributed to coal combustion and vehicle emissions, while principal component analysis-multiple linear regression further indicated that primary emissions and secondary formation jointly influenced the PAC content, accounting for 60.4% and 39.6%, respectively. The exposure risk of soil PACs was dominated by 16 priority control PAHs; the non-priority PAHs' contribution to the exposure risk was only 6.4%.