Occurrence of persistent organic pollutants in air at different sites in the province of Córdoba, Argentina

Contaminant dynamics in honey bees and hive products of apiaries from environmentally contrasting Argentinean regions

Argentina is a leading honey producer and honey bees are also critical for pollination services and wild plants. At the same time, it is a major crop producer with significant use of insecticides, posing risks to bees. Therefore, the presence of the highly toxic insecticide chlorpyrifos, and forbidden contaminants (organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs)) was investigated in honey bee, beebread, wax and honey samples in apiaries from three contrasting regions of Argentina. Chlorpyrifos was detected in all samples with higher levels during period 1 (spring) in contrast to period 2 (fall), agreeing with its season-wise use in different crops, reaching 3.05 ng/g in honey bees. A subsequent first-tier pesticide hazard analysis revealed that it was relevant to honey bee health, mainly due to the high concentrations found in wax samples from two sites, reaching 132.4 ng/g. In addition, wax was found to be the most contaminated matrix with a prevalence of OCPs (∑OCPs 58.23-172.99 ng/g). Beebread samples showed the highest concentrations and diversity of pesticide residues during period 1 (higher temperatures). A predominance of the endosulfan group was registered in most samples, consistent with its intensive past use, especially in Central Patagonia before its prohibition. Among the industrial compounds, lighter PCB congeners dominated, suggesting the importance of atmospheric transport. The spatio-temporal distribution of pesticides shows a congruence with the environmental characteristics of the areas where the fields are located (i.e., land use, type of productive activities and climatic conditions). Sustained monitoring of different pollutants in beekeeping matrices is recommended to characterize chemical risks, assess the health status of honey bee hives and the pollution levels of different agroecosystems. This knowledge will set a precedent for South America and be helpful for actions focused on the conservation of pollination services, apiculture and ecosystems in Argentina.

Air monitoring of organochlorine pesticides (OCPs) in Bursa Türkiye: Levels, temporal trends and risk assessment

Monitoring concentration levels of persistent organic pollutants (POPs) is required to evaluate the effectiveness of international regulations to minimize the emissions of persistent organic pollutants (POPs) into the environment. In this manner, we evaluated the spatial and temporal variations of 22 organochlorine pesticides (OCPs) using polyurethane foam passive air samplers at ten stations in Bursa in 2017 and 2018. The highest concentration value for Σ22OCPs was detected in Ağaköy (775 pg/m3) and Demirtaş (678 pg/m3) sampling sites, while the lowest value was observed in Uludağ University Campus (UUC, 284 pg/m3) site. HCB, γ-HCH, Endo I, and Mirex were the most frequently detected OCPs, which shows their persistence. Diagnostic ratios of β-/(α + γ)-HCH have pointed to historical and possible illegal OCP usage in the study area. The seasonality of air concentrations (with spring and summer concentrations higher than winter and autumn concentrations) was well exhibited by α-HCH, β-HCH, ɣ-HCH, HCB, Endo I, and Mirex but not aldrin, dieldrin, and α-chlordane (CC). Levels of OCPs detected in ambient air in the current study were relatively similar to or lower than those reported in previous studies conducted in Türkiye. Back trajectory analysis was applied to identify the possible sources of OCPs detected in the sampling regions. The Clausius-Clapeyron approach was used to investigate the temperature dependence of OCP gas-phase atmospheric concentrations. The data showed that long-range atmospheric transport affects ambient air OCP concentrations in the study area.

Investigating industrial PAH air pollution in relation to population exposure in major countries: A scoring approach

Polycyclic aromatic hydrocarbons (PAHs) are common air pollutants worldwide, associated with industrial processes. In the general population, both modeling and field studies revealed a positive correlation between air PAH concentrations and urinary PAH metabolite levels. Many countries lack population urinary data that correspond to local PAH air concentrations. Thus, we proposed a scoring-based approximate approach to investigating that correlation in selected countries, hypothesizing that PAH air concentrations in selected regions could represent the national air quality influenced by industrial emission and further correlate to PAH internal exposure in the general population. This research compiled 85 peer-reviewed journal articles and 9 official monitoring datasets/reports covering 34 countries, 16 of which with both atmospheric PAH data and human biomonitoring data. For the air pollution score (AirS), Egypt had the highest AirS at 0.94 and Pakistan was at the bottom of the score ranking at -1.95, as well as the median in the UK (AirS: 0.50). For the population exposure score (ExpS), China gained the top ExpS at 0.44 and Spain was with the lowest ExpS of -1.52, with the median value in Italy (ExpS: 0.43). Through the correlation analysis, atmospheric PAHs and their corresponding urinary metabolites provided a positive relationship to a diverse extent, indicating that the related urinary metabolites could reflect the population's exposure to specific atmospheric PAHs. The findings also revealed that in the 16 selected countries, AirS indexes were positively correlated with ExpS indexes, implying that higher PAH levels in the air may lead to elevated metabolite urinary levels in general populations. Furthermore, lowering PAH air concentrations could reduce population internal PAH exposure, implying that strict PAH air regulation or emission would reduce health risks for general populations. Notably, this study was an ideal theoretical research based on proposed assumptions to some extent. Further research should focus on understanding exposure pathways, protecting vulnerable populations, and improving the PAH database to optimize PAH pollution control.

Removal mechanism of persistent organic pollutants by Fe-C micro-electrolysis

The degradation of persistent organic pollutants (POPs) in the simulated wastewaters was investigated by Fe-C micro-electrolysis system. With phenanthrene (PHE) and 2,4-dichlorophenol (2,4-DCP) as target pollutants, different iron-carbon (Fe-C) micro-electrolysis systems have been established. The effects of initial pH, Fe/C mass ratio, and intake air flow on the degradation and mineralization of PHE and 2,4-DCP were studied. At the initial pH of 5.0, Fe/C of 1.5:1, and an aeration flow rate of 1.5 L/min, after 120 min of reaction, the removal efficiency of FHE and COD was 94.3% and 73%, respectively. Under the conditions of initial pH is 3.0, Fe/C is 1:2, aeration flow rate of 1.5 L/min, and reaction time of 90 min, the best removal efficiency of 2,4-DCP can be obtained in the Fe-C micro-electrolysis system as 97% and COD removal efficiency can reach 76%. The results of kinetic studies show that the Fe-C micro-electrolysis process of PHE and 2,4-DCP follows pseudo-first-order kinetics. Commercial activated carbon (AC) was used for comparison under the same condition. The results indicated that the removal rate of organic pollutants and chemical oxygen demand (COD) of Fe-C micro-electrolysis were superior to that of AC. Analyze the structure of iron after reaction by SEM and XRD. The degradation pathway and mechanism for PHE and 2,4-DCP were proposed based on LC-MS analyses of treated wastewater.

Persistent organic pollutants: The trade-off between potential risks and sustainable remediation methods

Persistent Organic Pollutants (POPs) have become a very serious issue for the environment because of their toxicity, resistance to conventional degradation mechanisms, and capacity to bioconcentrate, bioaccumulate and biomagnify. In this review article, the safety, regulatory, and remediation aspects of POPs including aromatic, chlorinated, pesticides, brominated, and fluorinated compounds, are discussed. Industrial and agricultural activities are identified as the main sources of these harmful chemicals, which are released to air, soil and water, impacting on social and economic development of society at a global scale. The main types of POPs are presented, illustrating their effects on wildlife and human beings, as well as the ways in which they contaminate the food chain. Some of the most promising and innovative technologies developed for the removal of POPs from water are discussed, contrasting their advantages and disadvantages with those of more conventional treatment processes. The promising methods presented in this work include bioremediation, advanced oxidation, ionizing radiation, and nanotechnology. Finally, some alternatives to define more efficient approaches to overcome the impacts that POPs cause in the hydric sources are pointed out. These alternatives include the formulation of policies, regulations and custom-made legislation for controlling the use of these pollutants.

Spatiotemporal distribution and human health risk assessment of potential toxic species in soils of urban and surrounding crop fields from an agricultural area, Córdoba, Argentina

The spatiotemporal distribution of potentially toxic species was studied in the topsoil of parks, playgrounds, and surrounding crop fields of Marcos Juarez City in Córdoba province, Argentina. The content of available metals and of some pesticides used in the region was determined. The mean values of available metal concentrations in all samples, expressed in mg kg^-1, were 7.99 ± 6.58, 0.89 ± 0.71, 0.35 ± 0.26, and 1.50 ± 1.40 for Pb, Cr, Cd, and Ni, respectively. Pearson's correlation coefficients, coefficient of variation (%), and principal component analysis were used to explore whether variations in metal content were associated with anthropogenic factors. Agrochemicals such as lindane, chlorobenzilate, endosulfan, endrin, permethrin, and chlorpyrifos were found in crop field soil samples. In turn, chlorothalonil, chlordanes, methoxychlor, DDT, permethrin, and chlorpyrifos were detected in park and playground soil samples. The degree of pollution with possible effects on environmental health was evaluated using the Nemerow integrated pollution index (NIPI) and the modified degree of contamination (mCd). In some campaigns, the values obtained from crop fields ranged from low to high pollution levels during periods of agrochemical application. Noteworthy, in periods of low agrochemical application in crop fields, a high level of pollution was observed in parks and playgrounds. For children, the hazard index (HI) values were higher than the threshold value of 1, suggesting a potential health risk. This study provides valuable information regarding land management practices and highlights the importance of monitoring and implementing policies to reduce human health risks.

The Research Progress of the Influence of Agricultural Activities on Atmospheric Environment in Recent Ten Years: A Review

In recent years, the industrial emission of air pollution has been reduced via a series of measures. However, with the rapid development of modern agriculture, air pollution caused by agricultural activities is becoming more and more serious. Agricultural activities can generate a large amount of air pollutants, such as ammonia, methane, nitrogen oxides, volatile organic compounds, and persistent organic pollutants, the sources of which mainly include farmland fertilization, livestock breeding, pesticide use, agricultural residue burning, agricultural machinery, and agricultural irrigation. Greenhouse gases emitted by agricultural activities can affect regional climate change, while atmospheric particulates and persistent organic pollutants can even seriously harm the health of surrounding residents. With the increasing threat of agricultural air pollution, more and more relevant studies have been carried out, as well as some recommendations for reducing emissions. The emissions of ammonia and greenhouse gases can be significantly reduced by adopting reasonable fertilization methods, scientific soil management, and advanced manure treatment systems. Regarding pesticide use and agricultural residues burning, emission reduction are more dependent on the restriction and support of government regulations, such as banning certain pesticides, prohibiting open burning of straw, and supporting the recycling and reuse of residues. This review, summarizing the relevant research in the past decade, discusses the current situation, health effects, and emission reduction measures of agricultural air pollutants from different sources, in order to provide some help for follow-up research.

Passive air sampling for semi-volatile organic chemicals

During passive air sampling, the amount of a chemical taken up in a sorbent from the air without the help of a pump is quantified and converted into an air concentration. In an equilibrium sampler, this conversion requires a thermodynamic parameter, the equilibrium sorption coefficient between gas-phase and sorbent. In a kinetic sampler, a time-averaged air concentration is obtained using a sampling rate, which is a kinetic parameter. Design requirements for kinetic and equilibrium sampling conflict with each other. The volatility of semi-volatile organic compounds (SVOCs) varies over five orders of magnitude, which implies that passive air samplers are inevitably kinetic samplers for less volatile SVOCs and equilibrium samplers for more volatile SVOCs. Therefore, most currently used passive sampler designs for SVOCs are a compromise that requires the consideration of both a thermodynamic and a kinetic parameter. Their quantitative interpretation depends on assumptions that are rarely fulfilled, and on input parameters, that are often only known with high uncertainty. Kinetic passive air sampling for SVOCs is also challenging because their typically very low atmospheric concentrations necessitate relatively high sampling rates that can only be achieved without the use of diffusive barriers. This in turn renders sampling rates dependent on wind conditions and therefore highly variable. Despite the overall high uncertainty arising from these challenges, passive air samplers for SVOCs have valuable roles to play in recording (i) spatial concentration variability at scales ranging from a few centimeters to tens of thousands of kilometers, (ii) long-term trends, (iii) air contamination in remote and inaccessible locations and (iv) indoor inhalation exposure. Going forward, thermal desorption of sorbents may lower the detection limits for some SVOCs to an extent that the use of diffusive barriers in the kinetic sampling of SVOCs becomes feasible, which is a prerequisite to decreasing the uncertainty of sampling rates. If the thermally stable sorbent additionally has a high sorptive capacity, it may be possible to design true kinetic samplers for most SVOCs. In the meantime, the passive air sampling community would benefit from being more transparent by rigorously quantifying and explicitly reporting uncertainty.

Physiological Response and Multi-Elemental Content in Lichens Growing on Agricultural Fences: A Pilot Study Comparing No-Tillage and Organic Cropping

The objective of this study is to compare the physiological response (content and degradation of photosynthetic pigments, membrane oxidation products and soluble proteins) and multi-element content of Ramalina celastri (lichenized fungi) growing on agricultural fences with no-tillage (associated with transgenic crops and agrochemical application), organic cropping and a non-cultivated area. We found that R. celastri did not differ in its physiological response to agricultural practices, except for the contents of chlorophyll b and phaeophytin a which were high in both cultivated areas. Lichens growing in organic cropping fields have higher arsenic, chromium, uranium and internal transition elements common in the earth's crust, possibly due to the greater resuspension of the material during soil tillage. Lichens that grow on posts close to no-tillage field had higher bromine contents (present in numerous pesticides). We found evidence that R. celastri behaves as a tolerant species to air pollution in agricultural environments.

Polyurethane foam-based passive air sampling for simultaneous determination of POP- and PAH-related compounds: A case study in informal waste processing and urban areas, northern Vietnam

Polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), hexabromobiphenyl (BB-153), novel brominated flame retardants (NBFRs), and unsubstituted/methylated polycyclic aromatic hydrocarbons (PAHs/Me-PAHs) were simultaneously monitored in the air samples collected from Vietnamese urban and vehicular waste processing areas by using polyurethane foam-based passive air sampling (PUF-PAS) method. Concentrations (pg m^-3) of organic pollutants decreased in the order: PAHs (median 29,000; range 5100-100,000) > Me-PAHs (6000; 1000-33,000) > PCBs (480; 170-1100) > PBDEs (11; 5.3-86) > NBFRs (0.20; n. d. - 51) > BB-153 (n.d.). The difference in total PCB and PBDE concentrations between the urban and waste processing air samples was not statistically significant. Meanwhile, levels of PAHs, Me-PAHs, benzo [a]pyrene equivalents (BaP-EQs), and toxic equivalents of dioxin-like PCBs (WHO-TEQs) were much higher in the waste processing sites. This is the first report on the abundance of mono- and di-CBs (notably CB-11) in the air from a developing country, suggesting their roles as emerging and ubiquitous air pollutants. Our results have indicated potential sources of specific organic pollutants such as dioxin-like PCBs, PAHs, and Me-PAHs from improper treatment of end-of-life vehicles and other vehicle related materials (e.g., waste oils and rubber tires), as well as current emission of PCBs and PBDEs in the urban area in Vietnam. Further atmospheric monitoring studies should be conducted in this developing country that cover both legacy and emerging contaminants with a focus on areas affected by rapid urbanization and informal waste processing activities.