Harbor emissions introduce carcinogenic polycyclic aromatic hydrocarbons (PAHs) into the marine environment, posing significant risks. This study investigated the distribution, sources, and risks of 16 priority PAHs in the atmosphere of Tianjin Harbor, one of the world's largest industrial harbors in northern China. A one-year sampling campaign from June 2020 to May 2021 was conducted to collect 35 samples for TSP, PM2.5, and gas phase, respectively, with surrogate recoveries ranging from 75%-125%. Annual mean total PAH concentrations in TSP, PM2.5 and gas phase were successively 104.49 ± 88.06 ng/m3, 56.19 ± 49.93 ng/m3, and 246.34 ± 169.30 ng/m3, with peak levels occurring in winter. The partitioning mechanism (slopes > -0.6) was dominated by the absorption into organic matter based on the gas-particle partitioning analysis, indicating strong local source influence. Local combustion sources, including biomass/coal burning (dominant in winter) and vehicle/ship emissions (year-round) were identified as the main contributors based on convergent evidence from PSCF, diagnostic ratio analysis, and positive matrix factorization (PMF). The incremental lifetime cancer risk (ILCR) from inhalation exposure exceeded the acceptable level of 10-6, with >99% of Monte Carlo simulations indicating a potential carcinogenic risk. The estimated dry deposition flux of total PAHs (ΣPAHs 138.26 ± 114.87 μg/m2/day) was higher than values reported for other coastal regions, implying the substantial input to the adjacent Bohai Sea. These findings underscored the dominance of local combustion emissions and the associated health risks, while suggesting potential ecological concerns related to atmospheric PAH deposition, providing a scientific basis for targeted mitigation measures in major industrial harbors.
The spatial distribution, sources and ecological risk of 16 US EPA priority polycyclic aromatic hydrocarbons (PAHs) in surface soil from Liuxin area, Xuzhou, China was investigated in this study. Gas chromatography-mass spectrometry (GC-MS) analysis revealed ΣPAH concentrations ranging from 115.66 to 373.53 ng∙g-1 (mean: 196.26 ng∙g-1), with phenanthrene (Phe) exhibiting the highest mean concentration (51.18 ng∙g-1). Spatial analysis demonstrated a southeast-to-northwest concentration gradient, with maximum PAH levels observed in southeastern zones. PAH composition showed dominance of low-molecular-weight species (2,3 rings: 46.7 %), followed by 5,6 ring PAHs (28.3 %), and 4-ring compounds (24.9 %). Source apportionment using molecular diagnostic ratios (DR) and positive matrix factorization (PMF) identified four primary contributors: coal-fired power generation & metallurgical emissions (34%), biomass combustion (31%), diesel fuel combustion/leakage (29%), traffic emissions (6%). Ecological risk assessment employing Dutch soil quality standards revealed localized exceedances in southeastern areas, particularly for fluoranthene (Fla) and Phe. However, toxic equivalency quotients (TEQs) remained low, with incremental lifetime cancer risks (ILCRs) below 10-6 for all exposure pathways. These findings indicate that while PAH contamination warrants monitoring, current levels pose negligible carcinogenic risk to the local population.
Jinxian He, Chen-Long Ding, Pei-Lin Sun et al.· Environmental Research Commu...· 0 citations
The open burning system of municipal solid waste (MSW) disposal releases varying concentrations of emissions into the atmosphere. One of such, Polycyclic Aromatic Hydrocarbons (PAHs) in the atmosphere have been documented to be a threat to humans. This study assessed the concentration of the ambient air PAHs in a MSW dumpsite at Egbedi, Osun State. A polyurethane foam (PUF) passive sampler was installed in 10 locations for 28 days to trap PAHs. The PAH results were subjected to a toxicity equivalence (TEQ), sources were identified by employing the existing diagnostic ratios, and inhalation dosage was investigated using the Excess Lifetime Cancer Risk Assessment (ELCR). The summation of the carcinogenic PAHs and the highest toxicity equivalence for rain and dry seasons were 0.241 µg/m3 and 0.369 µg/m3, and 0.070 and 0.110, respectively. The analysis revealed that the PAHs were mainly from the combustion of MSW. The ELCR values were (9.1 × 10–4) and (5.8 × 10–4), which were above the acceptable carcinogenic risk level of 1.0 × 10–6. The concentration of PAHs released is at a carcinogenic level and the TEQ and diagnostic ratio show that the emission source is from certain wastes. The PCA score plot showed a single cluster that was close to the center, indicating that the burning of MSW was the only source of emissions from the study location that added to the majority of the PAHs in the surrounding atmosphere. There is an urgent need to develop the dumpsite into a standard landfill.
O. Fadipe, Saheed Adekunle Adewale, O. B. Okedere et al.· Discover Environment· 0 citations
Organonitrogen pesticides (ONPs) are widely used in agriculture and can enter the ocean via surface runoff, posing potential threats to marine ecosystems. This study systematically investigated the occurrence and spatiotemporal distribution of 49 ONPs in seawater of the Beibu gulf, China, examined their key influencing factors, and conducted source apportionment and ecological risk assessment using multiple statistical models. The results showed that target ONPs were ubiquitously detected, with total concentrations (Σ49ONPs) ranging from 14.3 to 38.0 ng/L (mean: 20.2 ng/L). Spatially, higher concentrations were observed in the northern and central gulf, and lower in the southern area. Seasonally, the Σ49ONPs in summer 2022 (10.7-37.2 ng/L) were significantly higher than in winter (6.36-14.2 ng/L, p < 0.01), but comparable to summer 2021 (14.3-38.0 ng/L), with this seasonal pattern primarily linked to variations in riverine discharge. Correlation and random forest analyses identified terrestrial inputs and their interactions with suspended particulate matter (SPM) as critical drivers of ONP distribution and fate. Seawater Si:P ratios and Chl a concentrations serve as effective indicators of ONPs levels, while SPM acts as both a carrier and a sink. These findings underscore the necessity of integrating runoff management with pesticide application controls in coastal pollution mitigation. Multi-model source apportionment indicated that ONPs mainly originated from local agricultural applications and rubber industrial processing activities, with additional modulation by ocean currents and water exchange rates. Ecological risk assessment revealed that total ONPs concentrations posed moderate-to-high risks to marine organisms across trophic levels at most sampling sites, deserving particular attention.
Volatile organic compounds (VOCs) are the main precursors of ozone (O3) and secondary organic aerosols (SOAs), posing a significant threat to the environment and human health. In this study, the characteristics, potential for the generation of O3 and SOAs, sources and health risks of volatile organic compounds were investigated based on annual monitoring data for 2021 in Dezhou, which is located in the northwest of Shandong Province, China, and adjacent to the Beijing–Tianjin–Hebei region. The results showed that the ambient VOC concentrations were lower in spring and summer and higher in autumn and winter. The species contributing to the O3 formation potential (OFP) and SOA formation potential (SOAFP) varied by season, but those with high contributions were all olefins and aromatic hydrocarbons. O3 pollution occurred frequently in summer, with a proportion of 40.22%. Focusing on summer, six sources were identified through the positive matrix factorization (PMF) model, with the petrochemical industry (26.1%) and combustion (25.6%) being the primary sources. The non-carcinogenic risk values of the involved 18 toxic VOCs were all within the safety threshold, while the carcinogenic risk of benzene was regarded as low-probability under long-term exposure. This study provides significant support for targeted control of air pollutant emissions and improvement in regional air quality.
Wenbo Liu, Zongneng Tan, Fangping Wang et al.· Atmosphere· 0 citations
The results showed that no age group is fully protected, highlighting the need to include FA, AA, and acrolein in Brazilian air quality standards, to implement stricter controls on vehicle emissions, and to establish extensive, continuous atmospheric monitoring.
Mateus S. Moreira, Lícia P. S. Cruz· Air quality, atmosphere and...· 0 citations
Air pollution, particularly biomass burning (BB)–derived particulate matter (PM), remains a major challenge in Southeast Asia, affecting atmospheric processes, climate, human health, and socio-economic systems. This study presents the chemical characterization and source contributions of PM
0.49
at a rural site along the Thailand–Myanmar border in 2023. PM
0.49
concentrations showed pronounced temporal variability, with smoke-haze (SH) concentrations (67.9 ± 46.0 µg/m
3
) nearly six times higher than those during non-haze periods (non-SH; 10.9 ± 4.4 µg/m
3
). Organic carbon (OC) dominated during SH, accounting for 46% of PM
0.49
mass, followed by secondary inorganic aerosols (SO
4
2−
, NO
3
−
, NH
4
+
; 13%) and BB tracers such as K
+
(1.4%) and levoglucosan (2.7%), indicating strong BB influence. K⁺ exhibited strong correlations with levoglucosan (
r
= 0.95) and major anions (
r
= 0.52–0.94), highlighting its dual role as both a neutralizing cation and a BB tracer in both fresh and aged BB aerosols. Elevated OC to elemental carbon ratios (OC/EC; 13.4 ± 4.6) and char-EC/soot-EC ratios (9.68 ± 4.82) indicate smoldering BB as the principal source. Positive matrix factorization attributed 57% of PM
0.49
to BB during SH (up to 69% during peak phase), whereas soil dust dominated during non-SH conditions (70%). Backward trajectories and fire hotspot analyses suggest substantial cross-border transport from Myanmar. Furthermore, the seasonal shift in the effective carbon ratio (ECR), from 0.63 (SH) to 1.13 (non-SH), indicates a transition from light-absorbing to light-scattering aerosol dominance, underscoring the role of PM
0.49
in aerosol transformation under BB influence. These findings suggest air quality and potential climate implications, supporting coordinated mitigation.