US Environmental Protection Agency Research Articles

Petroleum sludge formation and its treatment methodologies: a review.

Different petroleum operations produce huge amount of oil sludge annually. For instance, US EPA estimates the annual sludge production of each US refinery of 30,000 tons, while the average oily sludge produced from petrochemical industries in China is estimated about 3 million tons per year. In the last year, our center could recover about 30,206 barrels of raw oil from 32,786 barrels of tank bottom sludge (TBS) for different petroleum companies. This sludge causes huge economic losses besides its negative environmental impacts. The accumulation of sludge in the tanks results in reducing the tanks' capacity for storing liquid crude, accelerating the corrosion of the tanks, delay in the production schedule, and disturbing the whole production operation. There are diverse treatment methodologies such as solvent treatment, addition of certain chemicals, and centrifuging. Of course, the environmental regulations and the overall cost limitations are very important in deciding the preferred applicable method(s). Although several works handled the problem of sludge deposition and treatment from different aspects, we intend to introduce a different work. First, composition, formation, types, and properties of TBS were reviewed. Then, environmental and economic problems caused by TBS were revised. At last, different methodologies applied for treatment of oily TBS to recover oil and safe disposal of hazardous remains were investigated focusing on the most straightforward and environmentally friendly protocols. It is expected that this review attracts the experts in petroleum chemistry, and other relevant fields and provides a comprehensive understanding of current sludge control and treatment research.

Appraisal of river sediments in southwestern Nigeria with a special focus on trace metals: Occurrence, seasonal variation, sources, and health risks

Metal toxicity can negatively affect aquatic biodiversity. In this study, eight trace metals (TMs) (Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) were determined in 72 sediment samples collected from six major rivers in Southwestern Nigeria between the dry and wet seasons of 2019 and 2021by inductively coupled plasma optical emission spectrometry (ICP-OES). Pollution indices such as enrichment factor, geo accumulation index, pollution load index, and potential ecological risk index were evaluated. At both seasons, the mean TM concentrations (mg/kg) followed a similar trend in decreasing order as Cu (589.32 ± 582.00) > Fe (269.52 ± 127.09) > Zn (162.68 ± 103.14) > Mn (61.89 ± 29.87) > Pb (10.09 ± 5.34) > Cd (8.59 ± 2.20) > Cr (8.72 ± 2.60) > Ni (3.16 ± 1.55) across locations and seasons. Distinctive distribution profiles characterized individual metals coupled with significant seasonal shifts in concentration (p < 0.05). Comparison with recommended national limits for Cd, Cu, Fe, Ni, Pb, and Zn suggested potential human and ecosystem health risks for the local population, while all the metals are above US EPA residential criteria. Cd displayed considerable, or very high ecological risks across all locations and seasons. Overall, Cd was considered a key potential ecological risk factor. Data revealed more anthropogenic than natural sources influenced sediment-bound TMs based on principal component analysis (PCA) and positive matrix factorization (PMF). The findings in this report provide fundamental information that would allow more effective monitoring through the establishment of critical policies and measures to reduce TMs levels in the environment.

Characterization of textile effluent treatment plant sludge and its industrial application in fired clay bricks with health risk assessment

The textile industry in Bangladesh faces environmental and health challenges due to the disposal of solid waste from Effluent Treatment Plants (ETPs). To address this issue, a study was conducted using soil from a brick industry near Dhaka, amending it with varying amounts of dry sludge to create clay bricks. The original soil had a loam texture and medium plasticity. The research found that adding 9 wt% of sludge resulted in Grade A commercial bricks with a compressive strength of 15.33 MPa and water absorption of 13.33 wt%, meeting BDS 208 standards. However, these sludge-incorporated bricks experienced more shrinkage during the burning process due to organic content, requiring additional soil to maintain conventional dimensions. Also, to assess the health hazards of these sludge-incorporated bricks, a leaching test was performed, revealing that no toxic heavy metals (Pb, Cd, Cr, Cu, Ni, and Zn) in the leachate exceeded the limits set by the United States Environmental Protection Agency (USEPA). The study indicates that textile ETP sludge can serve as a sustainable raw material for bricks, potentially reducing the environmental burden caused by textile sludge disposal by 28.75%. This innovative approach offers a promising solution to both environmental and health concerns associated with textile waste in Bangladesh's industrial sector.

The Role of Emission Size Distribution on the Efficacy of New Technologies to Reduce Methane Emissions from the Oil and Gas Sector.

Methane emissions from oil and gas operations exhibit skewed distributions. New technologies such as aerial-based leak detection surveys promise cost-effective detection of large emitters (greater than 10 kg/h). Recent policies such as the US Environmental Protection Agency (EPA) methane rule that allow the use of new technologies as part of leak detection and repair (LDAR) programs require a demonstration of equivalence with existing optical gas imaging (OGI) based LDAR programs. In this work, we illustrate the impact of emission size distribution on the equivalency condition between the OGI and site-wide survey technologies. Emission size distributions compiled from aerial measurements include significantly more emitters between 1 and 10 kg/h and lower average emission rates for large emitters compared to the emission distribution in the EPA rule. As a result, we find that equivalence may be achieved at lower site-wide survey frequencies when using technologies with detection thresholds below 10 kg/h, compared to the EPA rule. However, equivalence cannot be achieved with a detection threshold of 30 kg/h at any survey frequency, because most emitters across most US basins exhibit emission rates below 30 kg/h. We find that equivalence is a complex tradeoff among technology choice, design of LDAR programs, and survey frequency that can have more than one unique solution set.

Estimating impacts of LCRR's fifth-liter sampling and find-and-fix requirements on large water systems

This study demonstrates a data driven method for estimating fifth-liter water lead levels from first-liter water lead data.

Understanding the importance of atmospheric transformation in assessing the hazards of liquid crystal monomers.

Liquid crystal monomers (LCMs), a group of synthetic chemicals released from liquid crystal devices such as televisions and smartphones, have recently been recognized as emerging contaminants due to their widespread occurrence in the environment and potential negative impacts on human health. Airborne LCMs can undergo atmospheric oxidation reactions to form various transformation products. Despite the certainty of atmospheric transformation chemistry, the knowledge about the hazard properties of transformation products remains largely unknown. Here, we perform an in silico model-based evaluation of the persistence, bioaccumulation potential, mobility, and toxicity of two representative LCMs, namely, 1-ethyl-4-(4-(4-propylcyclohexyl)phenyl)benzene and 4''-ethyl-2'-fluoro-4-propyl-1,1':4',1''-terphenyl, and their transformation products. We found that, among the investigated transformation products, 38% have overall persistence greater than the minimum of 331 days among the persistent organic pollutants regulated by the Stockholm Convention, 62% meet the bioaccumulation threshold of 1000 L kg-1 used by the United States Environmental Protection Agency, 44% are classified "mobile" according to the criterion used by the German Environmental Agency, and 58% have the potential to induce unacceptable toxic effects in aquatic organisms. Furthermore, we identified several transformation products with increased persistence, bioaccumulation potential, and mobility compared to their parent compounds. These findings not only offer insights for prioritizing LCM transformation products for future risk assessment, but also underscore the significance of considering atmospheric transformation in the evaluation of environmental risks posed by emerging contaminants, including LCMs.

Surface ligand modified silver nanoparticles-based SERS sensing platform for ultrasensitive detection of the pesticide thiram in green tea leaves: roles of coating agents in sensing performance.

Silver nanoparticles (AgNPs) have been regarded as a highly promising substrate for surface-enhanced Raman scattering (SERS) sensors. In this study, we focused on the electrochemical synthesis method by developing three kinds of AgNPs using three different electrolytes: citrate (e-Ag-C), oleic acid (e-Ag-O) and fish mint (Houttuynia cordata Thunb.) extract (e-Ag-bio). The as-prepared AgNPs were characterized and then employed as SERS substrates to detect the pesticide thiram. The obtained results show that e-Ag-O exhibits the best SERS performance. The effect of the coating agent was explained by chemical and electromagnetic enhancements (CM and EM). Although thiram could absorb onto e-Ag-C at the highest level, allowing its Raman signal to be best enhanced via the CM, the smallest interparticle distance of e-Ag-O could have resulted in the largest improvement in the EM. Using e-Ag-O to develop SERS-based sensors for thiram, we obtain the impressive detection limit of 1.04 × 10-10 M in standard samples and 10-9 M in tea leaves. The linear ranges are from 10-4 M to 10-7 M and from 10-7 M to 10-9 M, covering the maximum residue levels for plant commodities established by the United States Environment Protection Agency and European Food Safety Authority (2-13 ppm ∼7.7 × 10-6 M to 5 × 10-5 M).

Indoor air quality analysis and sustainable practices

A constant supply of fresh air is vital for eliminating harmful bacteria and supporting the body's immune system against viruses and infections. Poor indoor air quality poses significant health risks, affecting human well-being and productivity. To address this issue, indoor air quality analysis is essential for enclosed spaces like homes, offices, and schools. According to the United States Environmental Protection Agency, indoor air can be up to 1000 times more polluted than outdoor air, with modern lifestyles leading to people spending 80-90% of their time indoors. Air pollution, as reported by the World Health Organization, causes 7 million deaths annually, primarily affecting the lungs and increasing the risk of cardiovascular diseases. Monitoring indoor air quality parameters such as CO2 and humidity levels is crucial for a healthy lifestyle. By utilizing sensors like MQ135 and DHT11, we can measure indoor pollutants and evaluate ventilation systems' effectiveness. Automation, such as using servo motors for ventilation, helps maintain safe indoor air quality levels. This approach can be implemented across various sectors, including schools, malls, and offices, to create healthier environments. Ultimately, indoor air quality analysis plays a vital role in enhancing indoor air quality and promoting occupant well-being.

Using a combination of quantitative culture, molecular, and infrastructure data to rank potential sources of fecal contamination in Town Creek Estuary, North Carolina.

Estuarine water quality is declining worldwide due to increased tourism, coastal development, and a changing climate. Although well-established methods are in place to monitor water quality, municipalities struggle to use the data to prioritize infrastructure for monitoring and repair and to determine sources of contamination when they occur. The objective of this study was to assess water quality and prioritize sources of contamination within Town Creek Estuary (TCE), Beaufort, North Carolina, by combining culture, molecular, and geographic information systems (GIS) data into a novel contamination source ranking system. Water samples were collected from TCE at ten locations on eight sampling dates in Fall 2021 (n = 80). Microbiological water quality was assessed using US Environmental Protection Agency (U.S. EPA) approved culture-based methods for fecal indicator bacteria (FIB), including analysis of total coliforms (TC), Escherichia coli (EC), and Enterococcus spp. (ENT). The quantitative microbial source tracking (qMST) human-associated fecal marker, HF183, was quantified using droplet digital PCR (ddPCR). This information was combined with environmental data and GIS information detailing proximal sewer, septic, and stormwater infrastructure to determine potential sources of fecal contamination in the estuary. Results indicated FIB concentrations were significantly and positively correlated with precipitation and increased throughout the estuary following rainfall events (p < 0.01). Sampling sites with FIB concentrations above the U.S. EPA threshold also had the highest percentages of aged, less durable piping materials. Using a novel ranking system combining concentrations of FIB, HF183, and sewer infrastructure data at each site, we found that the two sites nearest the most aged sewage infrastructure and stormwater outflows were found to have the highest levels of measurable fecal contamination. This case study supports the inclusion of both traditional water quality measurements and local infrastructure data to support the current need for municipalities to identify, prioritize, and remediate failing infrastructure.

Impact of the Mednogorsk copper smelter on human health and soil environmental quality in Orenburg Region, Russia

Nonferrous metal smelting operations are a recognized source of metal accumulation in surrounding soils. In Mednogorsk, Russia, soil contamination results from atmospheric emissions from a local copper (Cu) smelter. This study aimed to assess health risks by analyzing the levels of Cu, arsenic (As), cadmium (Cd), lead (Pb), and zinc (Zn) in 20 Mednogorsk topsoil samples and three background area samples. The phytotoxicity of metals to Lolium perenne was also evaluated. The soil ingestion protocol of the US Environmental Protection Agency was used for health risk assessment. Phytotoxicity tests were performed on ryegrass using a standard protocol. The levels of Cu correlated with those of other elements, indicating that the smelter was the source. Of concern, the carcinogenic risk exceeded the 10-04 threshold in 85% and 15% of the samples for children under five years of age and adults, respectively. In addition, 60% of the samples exceeded the safe Pb threshold for children's health (80 mg kg-1). These risk levels are unacceptable and require specific intervention by the relevant authorities. However, only 20% of the samples showed high phytotoxicity, mostly in acidic soils (pH&lt;4.0). This discussion focuses on the potential of soil phytostabilization to reduce human metal exposure, as the results provide valuable insights for managing metal pollution in regions affected by nonferrous smelter emissions worldwide.

Colorimetric sensing for the sensitive detection of UO22+via the phosphorylation functionalized mesoporous silica-based controlled release system.

In this study, we developed a simple and sensitive colorimetric sensing method for the detection of UO22+, which was built to release MB from the molybdenum disulfide with a phosphate group (MoS2-PO4) gated mesoporous silica nanoparticles functionalized phosphate group (MSN-PO4) with UO22+ chelating. In the presence of UO22+, MoS2-PO4 can be effectively adsorbed onto the surface of MSN-PO4 based on the coordination chemistry for strong affinity between the P-O bond and UO22+. The adsorbed MoS2-PO4 was then utilized as an ideal gate material to control the release of signal molecules (MB) entrapped within the pores of MSN-PO4, resulting in a detectable decrease in the absorption peak at 663 nm. This colorimetric sensing demonstrated the advantages of simplicity and easy manipulation and exhibited a linear response to the concentration of UO22+ within the range of 0.02-0.2 μM. The detection limit of UO22+ was determined to be 0.85 nM, which was lower than the limit (130 nmol L-1) set by the US Environmental Protection Agency. Furthermore, the proposed colorimetric sensing method has been utilized to determine UO22+ in samples of Xiangjiang River and tap water, and a high recovery rate was achieved. This method shows promising potential in preventing and controlling environmental pollution.

SDWA's 50th Anniversary Marked With Busy Agenda

The US Environmental Protection Agency (EPA) has continued to pursue an ambitious regulatory agenda for drinking water. Several significant final actions this year will require utilities to prepare.

Aptamer-functionalized gold nanoparticles for mercury ion detection in a colorimetric assay based on color change time as signal readout.

Auniversal strategy for a rapid colorimetric method for Hg2+ in an aqueous solutionis described. The specific binding of Hg2+ (thymine-Hg2+-thymine) with thiolated DNA-functionalized gold nanoparticles (AuNPs) via Au-S bonds increases the spatial hindrance of the AuNP surface, resulting in a weakened catalytic ability of AuNPs to catalyze the reaction between p-nitrophenol and NaBH4. Therefore, the color change time (CCT) of the solution from yellow to colorless becomes longer. Based on the kinetic curve of absorbance over time measured by a UV spectrometer, the level of Hg2+ in aqueous solutionscan be easily quantified. A linear relationship between CCT and Hg2+ concentration was obtained in the 10-600-nM range with a detection limit of 0.20nM, which is much lower than the limit value (10nM) defined by the US Environmental Protection Agency for Hg2+ indrinking water. The excellent sensitivity comes from CCT as the signal output of the probe, rather than the absorbance or wavelength change used in traditional colorimetric probes as the signal output.

Assessment of some toxic elements (Co, Cr, Mn, Se, and As) in muscle, offal, hair, and blood of camels (Camelus dromedaries) and their risk assessment.

Camel meat tainted with heavy metals or trace elements may pose a health risk to consumers. Heavy metal contamination poses a severe danger due to both their toxicity and bioaccumulation in the food chain. To estimate the residual levels of heavy metals (Co, Cr, Mn, Se, and As) in muscle, liver, kidney, hair, and serum of three camel breeds (Magaheem, Maghateer, and Wadha) collected from Al-Omran abattoir, Al-Ahsa, Saudi Arabia. A total of 225 tissue samples (muscles, liver, kidney, serum, and hair) were taken and analyzed using an Atomic Absorption Spectrophotometer. Health risk assessment was assessed using the guidelines set by the US Environmental Protection Agency. Camel breed significantly (p < 0.05) influences Co, Cr, Mn, and Se accumulation and distribution in organs and muscle; however, arsenic accumulation was not significantly affected (p < 0.05) by camel breeds. The highest values of Co, Cr, Se, and Mn in all examined samples were detected in the liver samples of Maghateer and Magaheem breeds. Furthermore, significant strong positive correlation between serum and liver cobalt, chromium, manganese, and arsenic. The estimated daily intake owing to camel meat consumption was less than the tolerated daily intake. Heavy metals were distributed among different breeds of camel. Trace elements (Pb and Cd) in meat and offal were below the international maximum permissible limit. The correlation between samples reflects the role of hair as a good tool for the identification of heavy metal pollution.

Application of the Key Characteristics Framework to Identify Potential Breast Carcinogens Using Publicly Available in Vivo, in Vitro, and in Silico Data.

Chemicals that induce mammary tumors in rodents or activate estrogen or progesterone signaling are likely to increase breast cancer (BC) risk. Identifying chemicals with these activities can prompt steps to protect human health. We compiled data on rodent tumors, endocrine activity, and genotoxicity to assess the key characteristics (KCs) of rodent mammary carcinogens (MCs), and to identify other chemicals that exhibit these effects and may therefore increase BC risk. Using authoritative databases, including International Agency for Research on Cancer (IARC) Monographs and the US Environmental Protection's (EPA) ToxCast, we selected chemicals that induce mammary tumors in rodents, stimulate estradiol or progesterone synthesis, or activate the estrogen receptor (ER) in vitro. We classified these chemicals by their genotoxicity and strength of endocrine activity and calculated the overrepresentation (enrichment) of these KCs among MCs. Finally, we evaluated whether these KCs predict whether a chemical is likely to induce mammary tumors. We identified 279 MCs and an additional 642 chemicals that stimulate estrogen or progesterone signaling. MCs were significantly enriched for steroidogenicity, ER agonism, and genotoxicity, supporting the use of these KCs to predict whether a chemical is likely to induce rodent mammary tumors and, by inference, increase BC risk. More MCs were steroidogens than ER agonists, and many increased both estradiol and progesterone. Enrichment among MCs was greater for strong endocrine activity vs. weak or inactive, with a significant trend. We identified hundreds of compounds that have biological activities that could increase BC risk and demonstrated that these activities are enriched among MCs. We argue that many of these should not be considered low hazard without investigating their ability to affect the breast, and chemicals with the strongest evidence can be targeted for exposure reduction. We describe ways to strengthen hazard identification, including improved assessments for mammary effects, developing assays for more KCs, and more comprehensive chemical testing. https://doi.org/10.1289/EHP13233.

Estimated mercury vapor exposure from amalgams among American pregnant women.

This study examined the impact of mercury (Hg) vapor exposure from amalgams among all American pregnant women. Amalgam-Hg vapor exposure among 1,665,890 weighted-pregnant women (n = 37) was examined in the 2015-2020 National Health and Nutrition Examination Survey (NHANES). Correlation coefficients between amalgam surfaces and daily micrograms (µg) of urinary Hg excretion and daily µg of Hg vapor exposure from amalgams per kilogram (Kg) bodyweight were calculated. Daily Hg vapor exposure from amalgams was compared to Hg vapor safety limits. About 600,000 pregnant women (∼36%) had at least one amalgam surface. Median daily urinary Hg excretion was ∼2.5-fold higher among pregnant women with amalgams as compared to pregnant women without amalgams. A significant correlation was observed between the number of amalgam surfaces and daily urinary Hg excretion. Among pregnant women with amalgams, it was estimated that the median daily Hg vapor dose from amalgams was 7.66 µg of Hg and 0.073 µg of Hg/Kg bodyweight. Among all pregnant women, ∼28% received daily Hg vapor doses from amalgams above the least restrictive United States (US) Environmental Protection Agency (EPA) safety limit and ∼36% received above the most restrictive California (CA) EPA safety limit. Given the potential for fetal toxicological effects from prenatal Hg vapor exposure, special emphasis needs to be placed on reducing/eliminating amalgams in pregnancy/women of reproductive age and future studies should evaluate adverse pregnancy outcomes.

Assessment of Trace Metal Contamination in Bivalve, Mytilus galloprovincialis, By Bioconcentration Factor (BCF) in the Moroccan Mediterranean Coast Environment

This study investigates the pollution of Morocco’s Mediterranean coastal zones by trace metals, highlighting its significance due to detrimental impacts on marine ecosystems and potential health risks through the food chain, exacerbated by the expansion of coastal areas in recent years. It focuses on measuring concentrations of trace metals such as copper, cadmium, lead, and chromium in the bivalve Mytilus galloprovincialis and surrounding seawater across three sites along the northern Moroccan Mediterranean coast. This research aims to evaluate metal bioaccumulation levels using the Biota Concentration Factor (BCF). Seawater samples were examined using both flame and graphite furnace atomic absorption spectrophotometry, while bivalve tissue samples underwent analysis through Inductively Coupled Plasma Optical Emission Spectrometry. Findings indicate that M. galloprovincialis significantly accumulates trace metals, with concentrations in descending order: Pb, Zn, Cr, Cu, and Cd. Conversely, the seawater metal concentration sequence was Zn, Cu, Cr, Cd, and Pb. The study applied BCF thresholds from Regulation (EC) No 1907/2006 (REACH) and the US EPA’s Toxic Substances Control Act (TSCA), categorizing metals as “bioaccumulative” (BCF between 1000 and 5000) and “very bioaccumulative” (BCF over 5000). This distribution provides insights into the toxicity and bioaccumulation of metals, underscoring the environmental and health implications for the marine ecosystem and species like M. galloprovincialis.

Analyzing Granular and Membrane Filters for Rainwater Treatment: A Comparative Study

The aim of this research was to evaluate the effectiveness of rainwater treatment using two distinct filtration methods: one utilizing traditional filtration materials (gravel, sand, and anthracite), and the other employing membranes. In both cases, the quality of the treated rainwater met the standards set by NBR 15527:2007 (Brazilian Association of Technical Standards) and the United States Environmental Protection Agency (EPA) for non-potable purposes, including parameters such as pH, temperature, turbidity, ammonia, nitrate, nitrite, alkalinity, and calcium hardness. Furthermore, the findings were compared with Brazilian Ministry of Health Directive 2914/2011, which pertains to water potability, and Resolution 357/2005 of CONAMA (Brazilian National Council for the Environment), addressing surface water bodies, particularly rivers, and permitting direct human skin contact with water. The study concluded that rainwater treated by both filtration methods could be utilized for various non-potable applications such as toilet flushing, garden irrigation, and sidewalk cleaning, as well as for direct-contact activities like bathing and laundry washing.

Human health risk assessment of intake Cd and Cu from agricultural soils in Mostar and Tomislavgrad

The aim of the research was to determine the total content of cadmium (Cd) and copper (Cu) in agricultural soils and to determine the potential toxicity of different intake routes for children and adults. Two locations were selected (Tomislavgrad and Mostar) where field crops were grown. Taking soil samples and determining the content of Cd and Cu was carried out according to the Instructions on determining the permitted amounts of harmful and dangerous substances in the soil and their testing methods (Official Gazette of FBiH, no. 96/22). A health risk assessment model based on the guidelines of the US Environmental Protection Agency (USEPA, 1996; USEPA, 2002; USEPA, 2011) was used to calculate the human health risk assessment. The measured values of the total content of copper and cadmium at the Tomislavgrad location are in accordance with the prescribed limit values. The copper content at the Mostar location was 205.90 mg/kg, which is above the limit value, and the cadmium content is in accordance with the prescribed limit values. When the HI value is less than 1, then there is no risk to human health, but if the values are greater than 1, then there is concern about non-carcinogenic risks (USEPA, 2004). The USEPA considers a carcinogenic risk in the range of 1×10–6 to 1×10−4 to be acceptable to human health. Calculations for non-carcinogenic and cancerous health risks were following the limit values.

Toxicological Risk Evaluation of Polycyclic Aromatic Hydrocarbons in Soils from a Petroleum Spillage Site at Kokori in the Niger Delta Region of Nigeria

Polycyclic aromatic hydrocarbons (PAHs) are widespread environmental contaminants that are produced by the incomplete combustion of organic sources and are widely found in soils. This present research was carried out to evaluate the concentrations and toxicological risk assessment of the United States Environmental Protection Agency's sixteen priority polycyclic aromatic hydrocarbons (16 priority PAHs) in soils from the vicinity of an oil spillage site in Delta State of Nigeria. The level of pollution and potential toxicological health hazards of the PAHs were assessed in surface soil samples using soxhlet extraction of and Gas Chromatography-Mass Spectrometry (GC-MS). Thirteen out of the sixteen USEPA priority PAHs were detected in the soil sample. The concentrations of PAHs in the petroleum-contaminated soils in this investigation ranged from 0.01181 ppm to 1.16054 ppm, with the total estimated concentration of the 16 priority PAHs being 5.6713 ppm. Furthermore, the distribution of the PAHs in the study area was predominated by LMW PAHs (62%) over HMW PAHs (38%). Additionally, the total toxicity equivalency quotients TEQ (B[a]Peq) result of the carcinogenic potency of the USEPA priority PAHs was calculated as 0.08689 ppm (8.689%) and was discovered to be within the Canadian TEQ (B[a]Peq) threshold of 0.6 ppm. This suggests that the soil in the study area is safe based on the Canadian TEQ (B[a]Peq) standard and does not constitute a carcinogenic risk. However, the long-term bioaccumulation of these low quantities of PAHs in human has been found to constitute a potential health concern due to bioaccumulation in living systems.