Suspended Particulate Matter Research Articles

Organic carbon, major and trace element release from and adsorption onto particulate suspended matter of the Ob River, western Siberia

Particulate suspended matter (PSM) of rivers is a significant factor for carbon, nutrient, and trace metal transfer from land to ocean. Towards better understanding the role that PSM exerts on major and trace elements in riverine systems, here we report the results of an experimental study which utilizes a two-fold approach to assess interaction between PSM and riverine solutes. First, we measured element leaching (via desorption and dissolution in distilled water, simulating snow melt) from PSM of the largest Siberian river, the Ob River. Second, we quantified the capacity of PSM to adsorb dissolved organic carbon (DOC), macro- and micronutrients and trace elements from organic-rich waters of the river floodplain. We documented sizable desorption of organic carbon, some major and trace metals, oxyanions and insoluble elements from PSM; the majority (>50 %) of elements were released over the first hour of reaction. In contrast, PSM of the Ob River was capable of removing 20 to 90 % of dissolved OC, nutrients (Si, P), and trace elements from the tributary and floodplain fen. Our experiments demonstrated preferential adsorption of aromatic compounds large molecular size colloids. Taken together, the adsorption of solutes by PSM can sizably decrease the concentration and modify the molecular size distribution, and therefore the potential bioavailability of major (DOC, P, Si) and trace micronutrients. Overall, the PSM of the Ob River exhibited high reactivity with respect to natural waters and was capable of modifying the elemental composition of the tributary and floodplain fen waters. This transfer of organic carbon and nutrients in the surface-adsorbed (particulate) form is especially important during spring flood and requires specific consideration in short-term biogeochemical cycles of elements in continental waters.

Optimal ventilation strategies for balancing carbon dioxide and suspended particulate matter concentrations in vehicle cabins

Maintaining safe levels of carbon dioxide (CO2) and particulate matter (PM) in vehicle cabins during driving is essential to ensure driver safety and minimize health risks. However, while the fresh-air ventilation mode reduces the CO2 level, it also allows the ingress of PM pollutants from the external environment and hence increases the PM concentration in the cabin. Thus, effective ventilation strategies are required to optimize the air quality by balancing the average levels of CO2 and suspended PM within the cabin. Accordingly, this study performed computational fluid dynamics simulations to explore the effects of different air-conditioning ventilation modes on the indoor air quality in the cabin of a commercial sports utility vehicle. The simulations commenced by examining the optimal switching times between the recirculation and fresh-air modes that yielded an average CO2 concentration of less than 1000 ppm for various numbers of occupants in the cabin. Further simulations were then performed to investigate the effect of the air filtration efficiency of the in-cabin filter on the PM concentration in the cabin under the optimal ventilation strategies determined for 1–5 occupants. The results indicated that, as the number of occupants increased, the required fresh-air mode usage time also increased. Furthermore, to mitigate the corresponding increase in the PM concentration, a higher filtration efficiency was required. Overall, the results showed that the optimal switching cycles achieved the required indoor air quality within the cabin by successfully balancing the CO2 and suspended PM concentrations.

Dissolved and particulate metals and metalloids in the eastern Mekong Delta, Vietnam

The article reports the concentration levels of particulate and dissolved metals and metalloids (Be, Se, Sb, Tl, V, Pb, Cd, Cu, Zn, Ni, Mo, Co, Fe As, Ag) in the eastern region of the lower Mekong Delta (Vietnam) in order to assess their possible influence on the environmental quality of river water. To measure the concentrations of trace elements, a mass spectrometric method was used. The critical particulate elements had included V, Cu, Ni, Co, Pb, Cd and potentially critical – Mo, Ag, Se, Tl. In the dissolved phase these were Cu, Zn, and Pb, Cd, Co, Ag, Se respectively. The high accumulation ability of studied elements to suspended particulate matter (102–107) suggests their important role in the distribution of elements. The water salinization boundary in the riverbeds of the delta moves upstream 30–50 km further in the dry season compared to the wet season.

Land use and spatial contiguity are key driven factors of antibiotic multimedia patterns in the megacity river network

The widespread spread of antibiotics in the environment poses a growing threat to human health. This study investigated the distribution and fate of antibiotics concerning land use characteristics, hydrological conditions, and spatial contiguity within a megacity river network. Temporally, the average concentrations of twenty antibiotics in water (354 ng/L), suspended particulate matter (SPM) (46 ng/L), and sediment (151 ng/g) during dry season were notably higher than that in the corresponding environment media (water: 127 ng/L, SPM: 2 ng/L, and sediment: 49 ng/g) during the wet season. Moreover, the inter-annual variation of antibiotics in water showed a decreasing trend. Spatially, substantial antibiotic contamination was observed in a human-intensive watershed, particularly in the upstream and central city sections. The macrolides in water were most affected by land use types and hydrological processes. Antibiotic contamination in water exhibited a stronger spatial autocorrelation compared to other media. Nevertheless, the interconnectedness of antibiotic contamination in sediments during the wet season warrants attention, and relevant authorities should enhance environmental monitoring in watersheds with pollution hotspots. Certain antibiotics, such as sulfamethoxazole, enrofloxacin, and florfenicol, were transported via urban rivers to the ocean, potentially posing environmental risks to coastal water quality. Local sources accounted for the predominant portion (>50 %) of most antibiotics in various media. The correlation distances of antibiotics in waters during the wet season could screen ecological risk prioritization in aquatic environments.

SEM-EDS-based rapid measurement and size-fractionated speciation of airborne particulate matter and associated metals utilizing plant leaves.

This study was conducted to assess particulate matter pollution and the accumulation of airborne toxic metals by studying the foliar deposition pattern in an urban environment. To this end, two commonly growing plants (Senna siamea (Lam.) H.S.Irwin & Barneby and Alstonia scholaris (L.) R.Br.) from the busiest traffic squares of the city (Nehru Chowk) in Bilaspur, India, were selected for detailed study. For this purpose, plant leaf samples of both plant species were collected from pollution-affected areas and a reference site (unpolluted) in the city and examined by scanning electron microscopy and energy dispersive X-ray spectroscopy (SEM-EDS) to estimate the accumulation of PM-bound toxic metals at the leaf surfaces. The results of this study showed that the leaves of both plants accumulate PM in different size ranges. Although both plant leaves showed accumulation of PM from respirable suspended particulate matter (RSPM) to ultra-fine particles (UFPs: < 0.1: less than 100nm) range along with toxic metals, S. siamea retained a higher level of PM than A. scholaris due to better micro-morphological properties on both leaf surfaces. The size of some PM was found to be smaller than the stoma openings. The EDS study proved the presence of harmful airborne toxic metals (Pb, Cd, Cu, Zr, Al, Co, etc.) in these PMs of ambient air. This indicates that toxic metals can enter the leaves through stomatal openings. The results of this study recommended that both plants can be used as a tool to minimise PM pollution.

Distribution Characteristics of Atmospheric Microplastics in Typical Desert Agricultural Regions.

We examined the distribution characteristics of atmospheric microplastics in typical desert agricultural regions, with a focus on the agricultural areas surrounding the Taklamakan Desert, Xinjiang, China. We collected samples of total suspended particulate matter (TSP), atmospheric deposition, and atmospheric dust using both active and passive collection methods. The chemical composition, particle size, shape, and color of atmospheric microplastics were examined using a stereomicroscope and a Fourier-transform infrared spectrometer to analyze their characteristics. The results showed that the primary chemical compositions of microplastics included polypropylene (PP), polyethylene, polyethylene terephthalate, polymethylmethacrylate, and cellophane. Particle sizes were mainly within the range of 0 to 1000 μm. Fibrous microplastics constituted the majority of the TSP and atmospheric deposition, whereas film-like microplastics constituted the largest proportion of atmospheric dustfall. The deposition flux of atmospheric microplastics in the first quarter was measured at 103.21 ± 22.12 particles/m2/day, which was lower than that observed in conventional agricultural areas. The abundance of microplastics in atmospheric dustfall was found to be 1.36 particles/g. The proportion of PP microplastics in atmospheric dustfall can be as high as 35%. Through a comparison of microplastic content in TSP during dust storms and under normal weather conditions, it was found that dust storms can lead to an increase in the abundance of microplastics within the atmospheric TSP. The present study provides a scientific basis for understanding the distribution of atmospheric microplastics in typical desert agricultural regions. Environ Toxicol Chem 2024;43:1982-1995. © 2024 SETAC.

Tracing sources of inorganic suspended particulate matter in the Great Barrier Reef lagoon, Australia

Water clarity on the inshore Great Barrier Reef (GBR) is greatly influenced by terrestrial runoff of suspended particulate matter (SPM). Catchment sediment tracing studies often do not extend into the marine environment, preventing the analysis of preferential marine transport. This study employs novel collection and sediment tracing techniques to examine the transport of the terrigenous ‘mineral’ component of plume SPM within the GBR lagoon for two flood events. Utilising geochemical, radionuclide and clay mineral analysis, we trace terrigenous mineral sediments > 100 km from the river mouth. We show that the SPM geochemistry is highly influenced by particle-size fractionation, desorption, and dilution within the plume, rendering traditional tracing methods unviable. However, the ratios of rare earth elements (REE) to thorium (Th) provide stable tracers of mineral SPM transported across the catchment to marine continuum and allow the identification of discrete catchment sources for each flood event. Plume sediment radionuclides are also stable and consistent with sub-surface erosion sources.

Air Quality Predictions through Mathematical Modeling for Iron Ore Mine Project

Mathematical modeling was deployed to predict air quality during the construction and operation phases of an iron ore mine project in Maharashtra, India. A survey of different models revealed that the ISCST3 model was the most applicable one to predict the air quality parameters, particularly the suspended particulate matter (SPM) and coarse particulate matter (PM10). Baseline air quality data, emission rates, local meteorology, and terrain information were used to simulate the ground-level concentrations. The simulation predicted SPM and PM10 peaks of 172 µg/m3 and 44 µg/m3, respectively. The prediction was within the prescribed limits of the national standards of 200 µg/m3 and 100 µg/m3, respectively, near the source, with minor exceedances in total SPM in two nearby villages and an impact on air quality due to proposed mining. Accordingly, mitigation strategies towards such villages were recommended and implemented. Later, the monitoring in the operation phase revealed that particulate matter could be controlled effectively with mitigation strategies and ensured compliance with air quality standards. The analysis also revealed strong correlations between the particulate matter and the distance of the localities and SPM and PM10. Continuous monitoring and adaptive mitigation based on real-time data were thus emphasized for long-term sustainability and responsible mining practices.

Regional challenges concerning derivation of suspended particulate matter concentration and water turbidity from water reflectance. A case study in the western Black Sea

Assessment of water quality indicators, such as Suspended Particulate Matter (SPM) concentration and water turbidity (TUR) is essential for marine ecosystems health evaluations. This work focuses on the estimation of these two variables from water-leaving reflectance measurements, either derived from in-situ observations or satellite data, for the western Black Sea basin. The regional characteristics of the water optically active constituents can have important impact on the quality of such estimations if not properly accounted for. We test several existing inversion algorithms and quantify their accuracy. New, regionally adapted methods are then proposed, together with a new formulation for a multi-conditional switching mechanism. Calibration of these models is performed based on SPM and TUR in-situ measurements. It is shown that the improvements achieved through regional adaptation can be significant. Application of these algorithms to Sentinel-3 OLCI satellite data reveals the consistency of the proposed methodology. Also, it shows the degree of uncertainty if improper formulations are used, with major impact on the absolute values of retrieved SPM or TUR.

Temperature-dependent carbon isotope fractionation in coccolithophores

Introduction: The stable carbon isotope ratio of long-chain alkenones produced by marine haptophyte phytoplankton has often been used to estimate past variations in atmospheric CO2 throughout the Cenozoic. However, previous experimental studies and surveys of alkenones from surface sediment and suspended particulate matter document additional environmental and physiological influences on carbon isotopic fractionation in alkenones.Methods: To clarify the non-CO2 effects on the alkenone carbon isotope fractionations, an important alkenone producer, Gephyrocapsa oceanica, was cultured in laboratory. To separate effects of different environment parameters, G. oceanica was grown in continuous cultures under a matrix of environmental conditions in order to explore the influence of temperature independently of CO2(aq). Through careful manipulation of the media carbon system, we can control the variation of the media CO2(aq) independently of temperature solubility. Carbon isotope fractionations from alkenones, coccolith, and particulate organic carbon were measured from this steady state system.Results and Discussion: We find εp in alkenones and particulate organic carbon inversely correlates with temperature, and temperature affects εp more strongly than CO2(aq). The magnitude of the temperature effect can be explained by higher growth rates at warmer temperatures with a similar growth rate dependence as observed in previous cultures in which growth rate was regulated by other factors. Where the past temperature influence on growth rate could be constrained using the UK’37 alkenone index in the same samples, our finding offers an approach to deconvolve an important physiological factor affecting ancient alkenones εp, and may therefore improve past pCO2 estimates.

Air pollution mitigation and suspended particulate matter retention potential of selected plant species across seasonal variation in the urban area.

Air pollution is a pressing environmental concern in urban areas, especially in densely populated cities like Delhi, India. However, plant species can effectively capture airborne suspended pollutants. Given this, the present study aimed to investigate the seasonal variations (pre- and post-monsoon) in the pollution-mitigating potential, biochemical characteristics, and suspended particulate matter (SPM) capturing capacities of select plant species in Delhi. Also, using biochemical parameters, plant morphology, and socioeconomic factors, the study computed tolerance indices such as the Air Pollution Tolerance Index (APTI) and Anticipated Performance Index (API). Ficus religiosa L. exhibited the highest APTI value of 11.94, while Polyalthia longifolia (Sonn.) Thwaites displayed the lowest 7.99 APTI value during the pre-monsoon. Ficus benghalensis L. showed the maximum SPM adhesion on the leaves, with a deposition of 1305.46µg/cm2, whereas F. religiosa exhibited the lowest SPM deposition of 56.62µg/cm2. Moreover, the statistical analysis indicated a positive correlation between ascorbic acid and chlorophyll content (R2 > 0.6) with APTI. Also, F. religiosa demonstrated a significant Pearson's correlation (P < 0.05) between chlorophyll content and SPM deposition during the pre-monsoon. The study highlighted the dynamic nature of plant-based air pollution mitigation. It offered valuable insights into the potential of green infrastructure as a sustainable solution for addressing air quality concerns in urban environments. The results emphasized the significance of selecting adequate plant species and considering seasonal variations in developing urban greening strategies to combat air pollution.

Amphetamine-like substances and synthetic cathinones in Portuguese wastewater influents: Enantiomeric profiling and role of suspended particulate matter

Wastewater based epidemiology (WBE) has been used worldwide to estimate drug consumption routinely. Even though WBE provides valuable data to support legal and health interventions associated to drug use, monitoring studies in Portuguese wastewaters are scarce. Hence, this work aimed to estimate the consumption of some conventional abuse and illicit drugs such as amphetamine (AMP), methamphetamine (MAMP), 3,4-methylenedioxymethamphetamine (MDMA), and the synthetic cathinones buphedrone (BPD), butylone (BTL), 3,4-dimethylmethcathinone (3,4-DMMC) and 3-methylmethcathinone (3-MMC), considering not only the liquid phase, but also the suspended particulate matter (SPM). Moreover, the enantiomeric profiling of the samples was studied, exploring for the first time the possible enantioselective sorption of these drugs onto SPM. For that, 24 h composite raw wastewaters were collected from a conventional wastewater treatment plant (WWTP) in Portugal. After extraction, the liquid phase and SPM extracts were derivatized with an enantiomerically pure reagent and then, analysed using a gas chromatography-mass spectrometry (GC-MS) analytical method. The results showed a low and non-enantioselective adsorption to SPM at environmental relevant levels. Only (S)-AMP was detected in two SPM samples, whereas AMP, MAMP, MDMA, BPD, and 3,4-DMMC were detected in the liquid phase. AMP was the most frequently found drug with an estimated load up to 166.0 mg day−1 1000 people−1 and mostly found with enrichment of (S)-AMP. Nevertheless, (R)-AMP was also determined, which may be related to the consumption of either the illicit racemic AMP or the medicine (R)-deprenyl. The use of MDMA, MAMP and synthetic cathinones (BPD and 3,4-DMMC) was also suggested in Portugal. Nevertheless, the levels and the consumption estimate of the target chemicals were lower than in other European countries or worldwide. These findings provide the first step to the implementation of WBE monitoring campaigns to assess the status of drug consumption in Portuguese communities, contributing to the understanding of drug use patterns and trends worldwide and helping enforce preventive measures.

Geochemical Split Among the Suspended and Mud Sediments in the Nethravati River: Insights to Compositional Similarity of Peninsular Gneiss and the Deccan Basalt Derived Sediments, and Its Implications on Tracing the Provenance in the Indian Ocean

AbstractMajor, trace, and rare earth element (REE) geochemistry of sediments from a tropical mountain river is investigated to understand the behavior of chemical elements during weathering and transportation in a Peninsular Gneissic terrain. The results from this study are compared with the Deccan Basalt‐derived River sediments and the eastern Arabian Sea sediments with an intent to highlight the challenges associated with the provenance determination of sediments along the continental margin of India. The geochemistry of suspended particulate matter (SPM) and mud sediments (&lt;63 μm) of the Nethravati River indicate that sediments are derived from a relatively homogenous lithology, characterized by intermediate rocks of tonalitic (low‐Al TTGs) composition. The tectonic origin of the source rocks discriminated using sediment geochemistry suggests an ocean island arc origin. The sediments experience intense chemical weathering in the source region. The elemental composition and their inter‐element relationships suggest differential chemical weathering of mineral phases fractionate mafic components and their secondary mineral products in SPM, and mixed sources dominated by felsic components and their secondary mineral products in mud sediments. Intense chemical weathering induces significant geochemical splits among the suspended and mud sediments. The transport of mafic‐biased sediments from Peninsular India to Oceans, and the geochemical similarity with Deccan Basalt‐derived sediments makes it challenging to track the Peninsular Gneiss‐derived sediment provenance along the continental margin of India using conventional elemental geochemistry. The inferences from this study have important implications for determining the sediment provenance along the continental margin of India.

Variations in gaseous pollutants and suspended particulate matter over the season in the Darussalam area

Variations in gaseous pollutants and suspended particulate matter over the season in the Darussalam area

Subchronic particulate matter exposure underlying polyhexamethylene guanidine phosphate–induced lung injury: Quantitative and qualitative evaluation with chest computed tomography

Our study was to explore the effects of subchronic particulate matter (PM) exposure on lung injury induced by polyhexamethylene guanidine phosphate (PHMG-p) in a rat model. Specifically, we investigated pulmonary inflammation, fibrosis, and tumor formation using chest computed tomography (CT), and histopathologic examination. PHMG-p was administered intratracheally to 20 male rats. After an initial week of PHMG-p treatment, the experimental group (PM group) received intratracheal administration of PM suspension, while the control group received normal saline. This regimen was continued for 10 weeks to induce subchronic PM exposure. Chest CT scans were conducted on all rats, followed by the extraction of both lungs for histopathological analysis. All CT images underwent comprehensive quantitative and qualitative analyses. Pulmonary inflammation was markedly intensified in rats subjected to subchronic PM exposure in the PM group compared to those in the control. Similarly, lung fibrosis was more severe in the PM group as observed on both chest CT and histopathologic examination. Quantitative chest CT analysis revealed that the mean lesion volume was significantly greater in the PM group than in the control group. Although the incidence of bronchiolo-alveolar hyperplasia was higher in the PM group compared to the control group, this difference was not statistically significant. In summary, subchronic PM exposure exacerbated pulmonary inflammation and fibrosis underlying lung injury induced by PHMG-p.

Assessment of traffic-related PAH in various environmental components and its associated health risk at a highway Toll Plaza

Introduction: This study investigated Polycyclic Aromatic Hydrocarbon (PAH) emissions from road traffic at the Surathkal toll plaza, in Karnataka, India. It focuses on two phases: when the toll station operated (Phase 1: January 2020 – March 2020) and when it was inactive (Phase 2: January 2023 – March 2023). Materials and methods: The research examines Suspended Particulate Matter (SPM) concentration, its elemental analysis, and various PAH concentrations in it during both phases. Ultrasonic extraction and Gas Chromatography (GC) analysis were used to study 16 priority PAHs recommended by the United States Environmental Protection Agency (US-EPA), identifying eight in samples like SPM, soot, and green leaves. Inductively Coupled Plasma Optical Emission Spectrophotometer (ICPOES) analysed 14 elements in SPM. Results: Results revealed higher PAH concentration during Phase 2, indicating that the presence of toll structure negatively affects air quality even when inactive. In contrast, SPM and its elements had higher mean concentrations during Phase 1, suggesting an inverse relationship between SPM and PAH levels. PAH diagnostic ratios showed different sources for each phase, including gasoline, diesel, fossil fuel, coal/biomass, and pyrogenic sources. Comprehensive health risk assessment using BaP equivalent concentration (BaPeq) to estimate Inhalation Life-time Cancer Risk (ILCR), revealed an Conclusion: This research underscores the toll plaza's significant influence on air quality and calls for the development of mitigation measures.

Aerosol soluble proteins in Asian dust in southwestern Japan

Aerosol proteins, as core biological components of bioaerosols, are garnering increasing attention due to their environmental significance, including their roles in atmospheric processes and associated health risks. However, observational data on the proteins are very limited, leaving their distribution and variation in the atmosphere poorly understood. To investigate the long-distance transport of proteins with Asian dust in the Northern Hemisphere middle latitude westerlies to remote downwind areas, we quantified the soluble proteins in aerosol particles, referred to as aerosol soluble proteins (ASPs), collected in the coastal city of Kumamoto, Japan, during the spring of 2023, when three dust events occurred. The concentration of ASPs ranged from 0.22 to 1.68 μg m−3, with an average concentration of 0.73 ± 0.36 μg m−3 under dust conditions and 0.31 ± 0.05 μg m−3 under non-dust conditions. During the dust periods, the largest concentration of ASPs (1.68 μg m−3) coincided with the peak concentration of suspended particulate matter, and the concentration strongly correlated with the mass concentration of particles larger than 2.5 μm, indicating a close dependence of ASPs on dust particles. Primary estimations indicated a dry deposition flux of ASPs at approximately 1.10 ± 0.87 mg m−2 d−1 under the dust conditions. These results prove that Asian dust efficiently transports proteins, facilitating their dispersion in the atmosphere.

Joint associations of air pollutants during pregnancy, infancy, and childhood with childhood persistent asthma: Nationwide database study in Japan

The joint effect of air pollutants at relatively low levels requires further investigation. Here, a database study was performed to evaluate the effects of exposure to mixtures of air pollutants during pregnancy, infancy, and childhood on childhood persistent asthma. We used the Japan Medical Data Center database, which provides access to family linkages and healthcare provider addresses, and included child-mother dyads in which the child was born between January 2010 and January 2017. The exposure of interest was ground-level air pollutants, and the primary outcome was childhood persistent asthma at 45 years of age, as defined based on outpatient and inpatient asthma disease codes and/or asthma medication dispensing claims. The weighted quantile sum (WQS) regression was used to evaluate the effects of air pollutant mixtures on 52,526 child-mother dyads from 1149 of 1907 municipalities (60.3 %) in Japan. The WQS regression models showed that with every 10th percentile increase in the WQS index, ground-level air pollutants during pregnancy, infancy, and childhood increased the risk of childhood persistent asthma by an odds ratio of 1.04 (95 % CI: 1.02–1.05; p<0.001), 1.02 (95 % CI: 1.01–1.03; p<0.001), and 1.03 (95 % CI: 1.01–1.04; p<0.001), respectively. Moreover, particulate matter with an aerodynamic diameter ≤ 2.5 µm was assigned the highest weight across all three exposure periods. Relatively high weights were assigned to suspended particulate matter and photochemical oxidants during pregnancy, carbon monoxide during infancy, and photochemical oxidants during childhood. Our study showed that a mixture of low-level air pollutants has a detrimental association with childhood persistent asthma.

A preliminary investigation of occurrence of pharmaceuticals and personal care products in total suspended particulate matter in Ha Noi, Viet Nam

Air pollution has become a serious environmental issue in Viet Nam, particularly in large cities. There is little information regarding the presence of pharmaceuticals and personal care products (PPCPs) in suspended particulate matter in Ha Noi, Viet Nam. The present study screened 163 PPCPs from 12 total suspended particulate matter (TSP) samples collected in Ha Noi using a novel analytical method, the liquid chromatography-mass spectrometry-quadrupole time of flight-Sequential Window Acquisition of All Theoretical Fragment Ion Spectra method (LC-QTOF-MS-SWATH). We identified and quantified 6 of the 163 PPCPs. All of the 6 PPCPs were detected for the first time in TSP. The total concentration ranged from 37.3 to 401.0 pg m-3 (median: 143 pg m-3). The number of PPCPs detected per sample ranged from 1 to 5 (median: 3), and their figure found was higher in the nighttime than that of the daytime.

Assessment of organic contaminants at a paint manufacturing site: Implications for health risks and source identification

The daily variation of organic contaminants, both gaseous and associated with suspended particulate matter (PM), was investigated within the estate of the National Company of Paintings in Lakhdaria, Algeria, spanning the period 2014-2015. The research emphasizes the chemical characterization of suspended PM, analyzing a range of organic compounds, including n-alkanes, polycyclic aromatic hydrocarbons (PAHs), and highly polar organics (HPOC), such as phthalate esters and heterocyclic compounds. Vapors of PAHs and polychlorobiphenyls (PCBs) were also analyzed. Low molecular weight compounds were primarily associated with the gas phase (two-ring PAHs, approximately 95%; three-ring PAHs, around 70%), while high molecular weight congeners were mainly associated with the particle phase (six-ring PAHs, 55%). The concentrations of PCBs (ranging from 0.6 to 42 ng m–3) were higher than those reported in other cities in Algeria and Europe. The source reconciliation of organic contaminants through principal component analysis (PCA) demonstrated that the primary sources were petroleum combustion, industrial manufacturing, tobacco smoking, and vehicular traffic. The significance of tobacco smoke was further confirmed by the analysis of PAH diagnostic ratios. Differences in the rates of diagnostic ratios between gaseous and particulate PAHs were attributed to distinct contributions from sources such as industrial processes. Health risks for workers exposed to PAHs and PCBs in PM &lt; 10 μm (PM10) were quantitatively assessed in terms of benzo[a]pyrene equivalent concentration and incremental lifetime cancer risk (ILCR). The ILCR presents novel findings showcasing heightened risks among workers exposed to specific PAHs within production areas, whereas those related to PCBs suggested a high potential of health risks for laboratory workers.