Polycyclic Aromatic Hydrocarbons in Soil Organic Horizons Depending on the Soil Burn Severity and Type of Ecosystem

Land Degradation & Development

DOI: 10.1002/ldr.2806

Because forest fires are a source of polycyclic aromatic hydrocarbons (PAHs), the influence of burnt conditions is of paramount importance and has not been thoroughly studied yet. In this study, two types of forest stands (Pinus nigra and Pinus pinaster) and two shrubland systems (Erica arborea and Ulex europaeus), differing in litter properties (composition and flammability), were considered. Changes in PAH levels were analysed in unburnt and charred litter, and they were related to different levels of soil burn severity and the organic matter composition of the charred litter, including charcoal and/or ashes. For monitoring PAH levels, an analytical method to determine them in unburnt and burnt woodland samples by pressure liquid extraction using a solid phase extraction cleanup was optimized. The highest levels of PAHs were found in the charred litter of P. pinaster (especially at soil burn severity = 200–400 °C), followed by U. europaeus, which presented similar concentration than Erica arborea and, finally, P. nigra. An association between the low molecular weight PAHs and 50% burn‐off temperature differential scanning calorimetry supports the idea of fire smoke as the main source of low molecular weight PAHs in charred biomass generated at temperatures of 200–400 °C. Instead, the fraction of high molecular weight PAHs is related to hydrogen‐to‐carbon and oxygen‐to‐carbon ash‐free dry weight, with charring depending on their organic matter content in the burnt material. PAH mobility will depend on the solubility of the organic matter, which is higher at higher pHs. The higher risk is the transport downstream to rivers or wet systems.

Screening of organic pollutants in pet hair samples and the significance of environmental factors

Science of The Total Environment, 625 (2018) 311–319

10.1016/j.scitotenv.2017.12.270

Organic pollutants (OPs) represent a wide range of chemicals that are potentially harmful for human and wildlife health. Many of these pollutants have been identified as endocrine disruptors that can alter hormonal balance producing adverse biological effects such as neurotoxicity, reproductive disorders, carcinogenicity and hepatotoxicity. For years, hair has been selected as a non-invasive source to assess levels of animal contamination. In the present study, a multiclass screening method for determining about 60 organic pollutants in pet hair was designed and validated for qualitative and quantitative purposes. Concentrations from different classes of organochlorine, and organophosphate pesticides (OCPs, and OPPs), polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (NDL-PCBs and DL-PCBs), polybrominated diphenyl ethers (PBDEs) and organophosphate esters (OPEs) were identified in the selected pet hair samples from Ourense (NW, Spain). We detected most of these pollutants in the selected hair pets. The mean concentrations found ranged from 89 to 6556 ng/g for OPEs, from 8.6 to 1031 ng/g for PAHs, from 8.6 to 256 ng/g for PBDEs, from 29 to 184 ng/g for OPPs, from 0.29 to 139 for OCPs, from 0.30 to 59 ng/g for NDL-PCBs and from 1.2 to 14 ng/g for DL-PCBs. To our knowledge, this is the first study to document the presence of OPs in pets from North-West Spain and it could provide baseline information for future monitoring of OPs in the area.

Optimization of selective pressurized liquid extraction of organic pollutants in placenta to evaluate prenatal exposure

Journal of Chromatography A

https://doi.org/10.1016/j.chroma.2017.03.010

The early exposure to organic pollutants (OPs) related to dietary habit or environmental exposure is a concern of growing interest in environmental health. When OPs enter the body, they can accumulate in fatty tissue and even travel through the bloodstream being able to cross the placenta and reach the fetus through the substance exchange between the mother and the child. Epidemiologic and clinical data affirm that these chemicals increase the risk of adverse effects during childhood. This article reviews and addresses one of the most relevant analytical methods for determining OPs in placenta. We discuss and critically evaluate procedures, such as solid-liquid and selective pressurized liquid extraction (SPLE). Clean-up of extracts was performed by solid-phase extraction (SPE) using EZ-POP cartridges. Detection of OPs was carried out by gas chromatography (GC) coupled to tandem mass spectrometry (MS/MS). Recoveries ranged from 52% to 94% by SPLE with estimated quantification limits between 0.15 and 2.2 ng/g for organochlorine pesticides (OCPs), between 0.083 and 0.50 for organophosphate pesticides (OPPs), between 0.025 and 0.15 ng/g for polychlorinated biphenyl (PCBs), between 0.015 and 0.10 ng/g for polybromodiphenyl ethers (PBDEs), between 0.33 and 0.66 ng/g for pyrethroids and between 0.022 and 0.87 ng/g for polycyclic aromatic hydrocarbons (PAHs). Most of the target OPs were detected in twenty real placenta samples studied, with pyrethroids, PAHs and OPPs representing most of the 90% of OPs with means of 13–18 ng/g versus PCBs, OCPs, and PBDEs with means <4.0 ng/g. The rsults of this work indicate a prenatal exposure to OPs in Galicia.

Determination of kinetic bioconcentration in mussels after short term exposure to polycyclic aromatic hydrocarbons

Heliyon

DOI: 10.1016/j.heliyon.2017.e00231

The kinetic bioconcentration of N-heterocyclic aromatic hydrocarbons and polycyclic aromatic hydrocarbons in mussels (Mytilus galloprovincialis) after short waterborne exposure was studied. Benzo[a]pyrene (BaP), its analogue azaarene 10-azabenzo[a]pyrene (AzaBaP), and their mixture (Mix), were selected to monitor the changes in water concentrations over three days. Decay of both PAHs concentrations in water after 24 h of waterborne exposure to mussels at levels of 10 and 100 μg/L follows a first order kinetic with half-lives of 4–5 h, with residual levels of PAHs below 7%. While steady-state scenarios are well studied, there is a lack of information of what happens under non-steady-state conditions, the main purpose of our paper. A synergistic bioconcentration of the mixture was found (around 800 in the mix vs. around 400 for individual PAHs at 100 μg/L of waterborne exposure). It could be explained by the following reasons. The most polar AzaBaP does not compete with the most non-polar BaP for the same tissue compartments. Whereas BaP aggregate in hydrophobic areas, AzaBaP can also do in hydrophilic areas. Moreover, a chance for complex formation between them by charge-transfer stabilization mechanisms could make possible a higher bioaccumulation as a mixture. Instead, toxicological results suggest an additive behaviour in the mixture performance, dominated by BaP, which is the key PAH controlling phase I metabolization in mussels, since is approx. three times more toxic. These experiments provide useful indications for a rapid assessment of PAHs kinetic bioconcentration in mussels.

Organic pollutants profiling of wood ashes from biomass power plants linked to the ash characteristics

Science of the Total Environment, 544 (2016) 535-543

doi:10.1016/j.scitotenv.2015.11.134

Wood ash, characterized by high content of certain nutrients and charcoal, can be applied to soils as a means of managing this waste product improving the soil quality. The associated environmental risk must be assessed. The objective of this study was to characterize the bottom and fly ash collected from 15 biomass power plants in Spain by determining the benzene, toluene, ethylbenzene, xylene and styrene (BTEX + S), PAHs and aliphatic hydrocarbon contents of both types of ash. Biochar was also used for comparison purposes.

Profiling, distribution and levels of carcinogenic polycyclic aromatic hydrocarbons in traditional smoked plant and animal foods

Food Control, 59 (2016) 581–590

doi:10.1016/j.foodcont.2015.06.036

The purpose of this study was to evaluate the concentration of polycyclic aromatic hydrocarbons (PAH8 plus fluoranthene and pyrene) in “Pan de Cea” bread, “Pimentón de La Vera” paprika, “San Simón da Costa”, “Idiazábal” and “Humus” cheeses, and “Chorizo” garlic pork sausage. Results obtained showed that harmless low molecular weight compounds (Fluoranthene and Pyrene) represented the major contribution to the total PAHs. The most important PAHs according to the levels found were those in the 4 PAHs group (the rest of PAHs to add a total of 8 were contributing at very low levels). PAH4 and PAH8 levels showed percentages ranging from 6.0 to 7.0 % in bread, 16–17 % in paprika, 23–28 % in cheese and 20–24 % in meat sausages, respectively. B(a)P did not exceed the imposed limits in the EU. Bread showed the lower PAH concentration (3.4 μg/kg) followed by cheese (88 μg/kg), smoked sausage (1779 μg/kg) and paprika (9937 μg/kg). “Pimentón de la Vera” paprika is a condiment consumed in small quantities. The PAH profile had in common the decrease in PAH content as their molecular weight increased. These results showed that the contamination detected in “Pan de Cea” bread samples was very low, so that the consumption of this product does not pose a health risk. In cheese samples, the PAH contamination was detected meanly in rind, that accounted around the 100% of the total contamination. In meat sausages samples, the 90% of the total PAHs determined were accumulated in the casing. Considering the edible part, the PAH4 and B(a)P mean contents were below the limit established. Although, the highest PAH levels were detected in “Pimentón de la Vera” paprika, it should be pointed out that this product is a condiment consumed in small quantities and not in an everyday basis, it does not represent a risk for consumers. In cheese and meat sausage, according our estimates, the removal of the external part can be considered a good consumer practices to reduce the ingestion of PAHs.

A critical review about the health risk assessment of PAHs and their metabolites in foods

Critical Reviews in food science and nutrition, 55 (10), 2015, 1383-1405

DOI:10.1080/10408398.2012.697497

Polycyclic aromatic hydrocarbons (PAHs) are a family of toxicants that are ubiquitous in the environment. These contaminants generate considerable interest, because some of them are highly carcinogenic in laboratory animals and have been implicated in breast, lung, and colon cancers in humans. Dietary intake of PAHs constitutes a major source of exposure in humans. Factors affecting the accumulation of PAHs in the diet, their absorption following ingestion, and strategies to assess risk from exposure to these hydrocarbons following ingestion have received very little attention. This review, therefore, focuses on concentrations of PAHs in widely consumed dietary ingredients along with gastrointestinal absorption rates in humans. Metabolism and bioavailability of PAHs in animal models and the processes, which influence the disposition of these chemicals, are discussed. Finally, based on intake, disposition, and tumorigenesis data, the exposure risk to PAHs from diet is presented. This information is expected to provide a framework for refinements in risk assessment of PAHs.

Atmospheric pollutants in fog and rain events at the northwestern mountains of the Iberian Peninsula

Science of The Total Environment

Volumes 497–498, 1 November 2014, Pages 188–199

http://dx.doi.org/10.1016/j.scitotenv.2014.07.093

Atmospheric polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) are persistent organic pollutants (POPs) and exist in gas and particle phases, as well as dissolved or suspended in precipitation (fog or rain). While the hydrosphere is the main reservoir for PAHs, the atmosphere serves as the primary route for global transport of PCBs. In this study, fog and rain samples were collected during fourteen events from September 2011 to April 2012 in the Xistral Mountains, a remote range in the NW Iberian Peninsula. PAH compounds [especially of low molecular weight (LMW)] were universally found, but mainly in the fog-water samples. The total PAH concentration in fog-water ranged from non-detected to 216 ng · L− 1 (mean of 45 ng · L− 1), and was much higher in fall than in winter. Total PAH levels in the rain and fog events varied from non-detected to 1272 and 33 ng · L− 1 for, respectively, LMW and high molecular weight (HMW) PAHs. Diagnostic ratio analysis (LMW PAHs/HMW PAHs) suggested that petroleum combustion was the dominant contributor to PAHs in the area. Total PCB levels in the rain and fog events varied from non-detected to 305 and 91 ng · L− 1 for, respectively, PCBs with 2–3 Cl atoms and 5–10 Cl atoms. PCBs, especially those with 5–10 Cl atoms, were found linked to rain events. The occurrence of the most volatile PCBs, PCBs with 2–3 Cl atoms, is related to wind transport from far away sources, whereas the occurrence of PCBs with 5–10 Cl atoms seems to be related with the increase of its deposition during rainfall at the end of summer and fall. The movement of this fraction of PCBs is facilitated by its binding to air-suspended particles, whose concentrations usually show an increase as the result of a prolonged period of drought in summer.

Effect of Beer Marinades on Formation of Polycyclic Aromatic Hydrocarbons in Charcoal-Grilled Pork

J. Agric. Food Chem., 2014, 62 (12), pp 2638–2643

DOI: 10.1021/jf404966w

The effect of marinating meat with Pilsner beer, nonalcoholic Pilsner beer, and Black beer (coded respectively PB, P0B, and BB) on the formation of polycyclic aromatic hydrocarbons (PAHs) in charcoal-grilled pork was evaluated and compared with the formation of these compounds in unmarinated meat. Antiradical activity of marinades (DPPH assay) was assayed. BB exhibited the strongest scavenging activity (68.0%), followed by P0B (36.5%) and PB (29.5%). Control and marinated meat samples contained the eight PAHs named PAH8 by the EFSA and classified as suitable indicators for carcinogenic potency of PAHs in food. BB showed the highest inhibitory effect in the formation of PAH8 (53%), followed by P0B (25%) and PB (13%). The inhibitory effect of beer marinades on PAH8 increased with the increase of their radical-scavenging activity. BB marinade was the most efficient on reduction of PAH formation, providing a proper mitigation strategy.

Optimization of purification processes to remove polycyclic aromatic hydrocarbons (PAHs) in polluted raw fish oils

Science of The Total Environment

Volumes 470–471, 1 February 2014, Pages 917–924

http://dx.doi.org/10.1016/j.scitotenv.2013.10.061

Fish oils are one of the main sources of health promoting nutrients such as n − 3 fatty acids in animal and human diet. Nevertheless, they could be an important source of persistent organic pollutants (POPs). Different strategies of decontamination processes to reduce polycyclic aromatic hydrocarbon (PAH) levels in fish oils, such as solvent extraction (ethanol) and adsorbent extraction using commercially available (activated carbon) and sustainable adsorbents (mussel shell and wood ashes), were compared. Adsorption conditions were evaluated and optimized by an experimental design and the experimental results were adjusted to response surfaces. In this way, PAH removals increased with increasing of individual PAH molecular weight and they range from 80% to 100% using activated carbon and from 10% to 100% using wood ashes. Pine wood ashes showed similar removal rates to activated carbon (87%–100%) excluding F (51%) and P (42%). No PAH removal was observed using mussel shell ashes. Ethanol extraction was also optimized and showed a good performance in the extraction of PAHs. However, it does affect their ω − 3 fatty acid contents. Finally, real oil samples from different fishing areas: Spain, South America, and North Europe were selected for the decontamination experiments under experimental conditions previously optimized.