Polyaromatic hydrocarbons (PAHs) are a group of organic pollutants found commonly in aquatic systems around the world. They are composed of multiple aromatic rings fused together, Naphthalene being the lowest member. In this paper, we review all available data on the occurrence and trends of PAHs in aquatic environment. PAHs are fairly soluble in water, so they tend to sorb onto particulate matter and are readily deposited in sediments, therefore their occurrence in the aquatic environment has caused widespread concern. Several PAHs were found to be directly carcinogenic to mammals even in trace amounts. Both pyrogenic and petrogenic processes produce PAHs. The Pyrogenic PAHs result from the incomplete combustion of organic matter such as grass, coal, wood, natural gas, and petroleum, whereas petrogenic PAHs are derived from crude oil and its derivatives including lubricating oil, asphalt, gasoline, diesel etc. This paper is a review of source, fate, transport, and degradation of PAHs in aquatic environments, and also discusses toxicity, analytical methods and comparison of PAHs in different aquatic systems.

Microplastics (MPs) possess a strong capacity to adsorb and biodegrade slowly, resulting in substantial harm to the environment and potential health risks. In recent years, a flourishing study of MPs has led to valuable advancements. This review article presents a comprehensive bibliometric analysis of global microplastic pollution, providing a deep understanding of published data, current progress, research trends, and focal points. We conducted extensive searches in the Scopus and Web of Science Core Collection databases from 2012 to 2021, utilizing the widely used R software for analysis. Our findings demonstrate a significant increase in micro(nano)plastic publications, with a growth rate of 73.0% from 2012 to 2021. China emerges as the predominant contributor in this field. The journal Science of the Total Environment has published the highest proportion of relevant articles (16.1%) and received the most citations (9801). The analysis further emphasizes polymer products and MPs as key research areas in the past decade. This study serves as a fundamental basis for future investigations into micro(nano)plastic pollution’s impacts on terrestrial and aquatic ecosystems.

This research aims to comprehensively investigate the heavy metal contamination in road dust within the rapidly expanding urban area of Abeokuta, Nigeria. Focusing on potentially hazardous metals such as Cr, Co, As, Ni, Cu, Zn, Cd, Fe, and Pb, the study employs multivariate statistical techniques to identify sources, assess ecological and health hazards, and determine metal concentrations. Through the analysis of twenty road dust samples, variations in metal concentrations are observed, leading to the application of the geo-accumulation index, contamination factor, contamination degree, and pollution load index for contamination assessment. The results reveal varying degrees of contamination, with notable concentrations of Pb and Ni, indicating a deteriorating urban environment. Ecological risk assessments underscore potential threats to local flora and wildlife, while health risk evaluations emphasize urgent corrective actions needed, particularly for children exposed to heightened carcinogenic and non-carcinogenic hazards. Factor analysis and correlation studies unveil common anthropogenic origins for several metals, shedding light on the need for pollution mitigation techniques in the face of rapid urbanization and industrialization. The research contributes valuable insights to environmental and public health evaluations in the Abeokuta region, emphasizing the importance of informed decision-making for policymakers and the public.

Pakistan is a developing country and its population is growing rapidly. The trend towards economic growth and satisfying the needs of the growing population is increasing daily. For this purpose, industrial activities, vehicle emissions, and household-related activities pollute the atmospheric environment and release different types of toxic gases. Particulate matter assessments (PM2.5 and PM10) were reviewed in different cities of Pakistan. Respectively, the PM2.5 evaluation was carried out in 15 cities, while the PM10 concentration was in 18 cities in Pakistan. According to the review, the highest concentrations of PM2.5 were 302, 211.97, 88, 163.63, 113.09, 110.81, 110.81, 139.43, 126.97, 107.68, 109.81, 172, 150, 66, 354, 43.9, 2305 µg/m3 in Lahore, Faisalabad, Karachi, Gujranwala, Multan, Vehari, Bahawalnagar, Okara, Pakpattan, Jehlum, Sargodha, Peshawar Quetta, Islamabad, Haripur, Mingora, and Mardan (Jalala). Specifically, the highest concentration of PM10 were 301, 568, 638, 160.5, 200, 384.15, 301.38, 311.61, 700 µg/m3 in Lahore, Faisalabad, Peshawar, Charsada, Karachi, Gujranwala, Multan, Rawalpindi, and Quetta. Only, these cities are the most polluted in the whole country and the concentration of PM2.5 was above the normal range those prescribed by the National Environmental Quality Standred (NEQS). Commonly, the main problem is the suspended particulate matter (PM2.5 and PM10) in the atmosphere. The increasing level of pollution leads to different types of problems such as respiratory problems, eye irritation, throat infections, asthma, and cancer, and it also increases the level of death ratio in the country. The main reason for PM is the burning of solid waste near cities; industrial emission, vehicular emission, lack of proper green belt and solid waste management are the main reasons for atmospheric pollution. Given the existing state of the air, urgent action is required to address the low air quality.

In this study, particulate matter (PM) variation has been analyzed to address the dearth of scientific research on air pollution in a coastal city from south India. Mean PM2.5 and PM10 concentrations were 61.6 ± 26.4 and 87.3 ± 35.4 μg/m3. The highest (lowest) seasonal concentration was observed during winter (monsoon). Increase in PM from September to February is attributed to low relative humidity, biomass burning in nearby paddy fields, and continental air mass from the east and north-easterly direction. The mean PM2.5/PM10 ratio was 0.71, with the seasonal ratio ranging between 0.64 (summer) and 0.76 (monsoon), indicating the dominance of anthropogenic PM fraction. PM exhibited typical characteristic of the urban region, i.e., a two-peak diurnal trend during all seasons except monsoon. PM10 (PM2.5) concentrations decreased by ∼7–24.2% (∼11–21%) on the weekends, with the highest reduction in winter seasons. Regarding correlation analysis among PM, CO, and ozone; a negative correlation between PM10 and O3 and a positive correlation between PM and CO was observed. Wind speed and PM10 showed a positive quadratic linear, whereas wind speed and PM2.5 showed a negative linear relationship. The primary sources of particulate matter in Kannur town are motor vehicle emissions, dust from construction work in surrounding zones, and nearby industrial units.

The research aims to investigate the Cadmium (Cd) contamination in rice fields within Sleman Regency due to its potential environmental and human health impact. The study was conducted from January to June 2023 and involved collecting soil samples from 23 irrigated rice fields within Sleman Regency with a grid sampling approach. Composite soil samples were created by blending five individual sub-samples from the cultivated layer (0-20 cm). The Cd levels in these samples were investigated using the Atomic Absorption Spectro-photometer (AAS) method. The findings revealed that all the sampled rice fields in Sleman Regency exceeded the critical limit of Cd concentration. The analysis of contamination factors (CF) and potential ecological risks (Er) indicated that the Cd contamination in Sleman Regency had reached a highly polluted level, carrying potential ecological risks. The extent of Cd contamination, primarily resulting from human activities (EF > 1), fell within the severe to extreme range (I-geo = 4-5). As a result, remediation measures are required to address the Cd contamination in Sleman Regency’s rice fields. These findings call for reducing the usage of chemical fertilizers, pesticides, and fungicides. Future studies should determine the possibility of cadmium accumulation in rice and its transfer from soil to rice.

Mining activities and industrial production discharges often generate heavy metal pollution and pose serious environmental impacts. It is of great significance to study the pollution status and sources of heavy metals in polluted rivers for environmental pollution control. This paper determines the concentration of 34 heavy metals, including As, Cd, Cr, Cu, Ni, Pb, and Zn, in the Fengyuan River and tailing pond in Yunfu City, Guangdong Province. The potential ecological risk index (RI) and integrated pollution index (IPI) were used to evaluate the spatial distribution and pollution levels of heavy metals, and the possible source and enrichment of heavy metal were identified and assessed using enrichment factor (EF). The results showed that Cd and Tl in the slag of the tailings pond were the most serious; The potential ecological risk index indicates that Cd in the sediment of the Fengyuan River is a very severe ecological risk, As and Pb caused heavy and moderate ecological risk, respectively, while, Co, Cr, Cu, Mn, Ni, V, and Zn constituted mild ecological risks; The integrated pollution index shows that all the sampling sites are above high pollution. The average enrichment factor of Cd in surface sediments reached 28.11. The EF values of As, Cu, Mn, Pb, and Zn were all greater than 1. The RI, IPI, and EF produced similar levels of heavy metal pollution in sediments, thereby confirming each other’s results, indicating that the Fengyuan River is heavily contaminated, and As, Cd, Mn, Pb, and Zn were likely to have an effect on the aquatic ecosystem. According to principal component and hierarchical cluster analyses, the Fengyuan River may contain heavy metals from a variety of sources, such as tailings ponds, industrial parks, chemical effluent, and more. In addition, correlation analysis indicates that total organic carbon is significantly correlated with the concentrations of As and Cr, respectively, and combining EF suggests that cluster 1 containing As, Mn, and Pb and cluster 2 containing Cd and Zn may be derived from similar anthropogenic sources. This study can provide meaningful basic information for environmental development planning and decision-making associated with human health in the region.

Total ambient PM2.5 concentrations within six major metropolitan core-based statistical areas (CBSAs) were evaluated using a previously published approach that combines interpolation and fixed effect regression models to disentangle background from local PM2.5 contributions. The results demonstrate differences and similarities across the cities, including seasonal patterns, the magnitude of total PM2.5 concentrations, and local vs. background apportionment. Los Angeles generally had the greatest total and local PM2.5 concentrations, and monitoring locations in Seattle generally had the lowest total and local PM2.5 concentrations. In terms of seasonal change, mean total PM2.5 concentrations varied the most in Dallas and the least in Tampa, while mean total PM2.5 concentrations varied the most spatially in Los Angeles and the least spatially in Dallas. Additionally, mean local PM2.5 concentrations varied the most seasonally in Los Angeles and the least seasonally in Tampa, while mean local PM2.5 concentrations varied the most spatially in Seattle and the least spatially in Charlotte and Dallas. Local attribution in Charlotte, Dallas, Pittsburgh, and Tampa were most similar. Local attribution varied more widely in Los Angeles and Seattle. The analyses found distance to major U.S. roadways as an important indicator for total and local ambient PM2.5 concentrations. Accurate distinctions of local vs. background contributions and point vs. non-point source contributions allow for regulatory, mitigatory, and community efforts to be optimized at the appropriate spatial levels (i.e., local, regional, state, or national) and target toward the most impactful source sectors when seeking to take steps that reduce total community PM2.5 exposures (e.g., reducing vehicular emissions).

In this study, the activity concentrations of natural primordial radionuclides in fly ash (FA) samples collected from the landfill area of Afşin-Elbistan A lignite-fired thermal power plant (AE-A LFTPP) located in Kahramanmaraş province of Türkiye were measured using a gamma-ray spectrometer. Also, the radiological risk was assessed using the Residual Radioactivity Onsite 7.2 code. The average activity concentrations of 226Ra, 232Th and 40K in FA samples varied from 291 ± 10 to 853 ± 25 Bq/kg, 23 ± 1 to 125 ± 4 Bq/kg and 112 ± 10 to 315 ± 18 Bq/kg, respectively. The predicted maximum total annual effective dose rate due to the natural radionuclides and their progenies is 4.7, 4.4, and 4.0 mSv/y at t = 1000 y for 0.5-m, 1.25-m, and 2.0-m cover scenarios, respectively. While the predicted maximum total cancer risk is 4.56 × 10−3 (3.95 × 10−3 for 226Ra, 5.18 × 10−4 for 232Th and 6.14 × 10−15 for 40K), 4.00 × 10−3(3.80 × 10−3 for 226Ra, 1.90 × 10−4 for 232Th and 7.69 × 10−15 for 40K) and 3.71 × 10−3 (3.71 × 10−3 for 226Ra, 1.820 × 10−8 for 232Th and 7.66 × 10−15 for 40K) at t = 1000 y for 0.5-m, 1.25-m and 2.0-m cover scenario, respectively. Results also revealed that the total doses and cancer risks are less in thicker cover scenarios throughout the 1000 y time span and that 226Ra is the major contributor to the risk in all the scenarios owing to its higher activity concentration than 232Th and 40K.

The GIS mapping of the terrestrial γ -radiation levels and evaluation of the radiological health hazard to residents of Sapele, Oghara and Koko cities in Nigeria have been carried out, using a Digilert nuclear radiation survey meter, geographical positioning system (GPS) and arc ArcGIS software. In Sapele (4 zones), the measured average gamma radiation levels ranged from 0.011 ± 0.003 mR h − 1 to 0.014 ± 0.005 mR h − 1 , while in Oghara (5 zones), the average gamma radiation levels ranged from 0.013 ± 0.002 mR h − 1 to 0.026 ± 0.009 mR h − 1 and for Koko(4 zones), the values obtained ranged from 0.018 ± 0.003 mR h − 1 (1.54 ± 0.11 mSvy − 1 ) to 0.023 ± 0.008 mR h − 1 respectively, with overall mean value of 0.017 ± 0.006 mR h − 1 (1.43 ± 0.51 mSvy − 1 ) . The mean absorbed gamma dose rate for three cities of Sapele, Oghara and Koko are 106.50 ± 22.33 nGy h − 1 , 167.28 ± 22.59 nGy h − 1 and 176.80 ± 24.74 η Gyh − 1 respectively. The mean annual effective dose rate (AEDR) for the three cities is 0.13 ± 0.03 mSvy − 1 , 0.20 ± 0.07 mSvy − 1 and 0.22 ± 0.06 mSvy − 1 mSvy − 1 respectively , while the mean excess lifetime cancer risk (ELCR) values are (0.47, 0.72 and 0.77) x10−3 respectively. The results obtained in the cities indicate that the BIR levels, and corresponding estimated health risk parameters in Koko > Oghara > Sapele. The estimated effective dosage to organs shows that liver receiving the least dose of 0.07mSvy−1 (11%) while testes got the highest dose of 0.12 mSvy−1 (19%). The overall results obtained show that all the thirteen zones’ BIR levels and their estimated risk parameters exceeded their recommended limits for the public and were also higher than reported values in previous studies reviewed. The reported significant elevation of the obtained background ionizing radiation (BIR) values may not necessarily establish any immediate likelihood of radiological health risk, but call for caution on possible accumulative radiation effects in future on the residents of the study area.