The use of manures for detection and quantification of polycyclic aromatic hydrocarbons and 3-hydroxybenzo[a]pyrene in animal husbandry

The influence of meteorological conditions during traditional smoking on polycyclic aromatic hydrocarbon content in traditional Polish pork ham

The aim of the study was to examine the influence of meteorological conditions observed during the process of traditional smoking on polycyclic aromatic hydrocarbon content in traditional Polish pork ham. The material of the study comprised traditional Polish pork ham, one of the most frequently purchased and consumed meat products in Poland. The analysed ham was smoked with the traditional method using beech chips and pieces. Smoking time was four hours. During laboratory research the basic chemical composition of the product was examined. Using the HPLC method, the level of 15 selected Polycyclic Aromatic Hydrocarbons (PAHs). The obtained results show that the level of selected polycyclic aromatic hydrocarbons in the examined material depended on atmospheric pressure and relative air humidity. Atmospheric pressure significantly influenced the content of benzo(b)fluoranthene, benzo(a)anthracene and indeno(c,d)pyrene. Relative humidity impacted the absorption level of 5-methylchrysene, benzo(a)pyrene, benzo(b)fluoranthene, benzo(g,h,i)perylene, benzo(j)fluoranthene and indeno(c,d)pyrene. An influence of air temperature during the smoking process on PAHs content in the product was not observed. The results indicate that traditional smoking should be conducted under conditions of high relative humidity – ideally above 75%, and high atmospheric pressure – above 1000 hPa.

Molecular dynamics simulation of the interaction of water and humic acid in the adsorption of polycyclic aromatic hydrocarbons

Humic acid (HA) and water play an important role in polycyclic aromatic hydrocarbons (PAHs) adsorption and biodegradation in soil. In this work, molecular dynamics (MD) and electrostatic potential surfaces (EPSs) simulations are conducted to research the contribution of quartz surface, leonardite humic acid (LHA), and water to PAH adsorption. The adsorption energies between PAHs and LHA are much higher than that between PAHs and quartz. Simulation shows that the hydroxyl and carboxyl groups' attraction by LHA is the main adsorption force between PAHs and LHA. The π-π interaction between PAHs and LHA also contributes to the adsorption process. In addition, the mobility of water on quartz surface is much higher than that of LHA. Water should be regarded as an adsorbate in the system as well as PAHs. However, the presence of water has a remarkable negative effect on the adsorption of PAHs on LHA and quartz. The bridging effect of water could only enhance the stability of the aggregation system. The adsorption contribution of quartz and LHA to PAHs in the soil model tends to 0 if the water layer reaches 2.0 nm. Graphical abstract.

Innovative design of a methodology for the simultaneous determination of compounds by kinetic-spectroscopy three-dimensional chemiluminescence

This report presents a novel methodology based in the quickly acquisition of full UV-vis range spectra combined with the joint determination of kinetic parameters and chemiluminescence signals. Then this technique allows obtaining three-dimensional chemiluminescence spectra profiles containing kinetic and spectroscopic information. That is especially useful for resolving mixtures of luminophors because of more analytical information for each analyte is available increasing the selectivity relative to conventional chemiluminescence methods. To accomplish this, a conventional Back-Thinned CCD detector is used and the three-dimensional chemiluminescence spectra is subsequently processed so that two-dimensional spectra with different trajectories can be obtained by dedicated software CLTotal. The potential of the proposed analytical methodology was assessed for the simultaneous determination of two polycyclic aromatic hydrocarbons. The chemiluminescent reaction between DNPO and hydrogen peroxide induced by their presence was used to record 3D spectra and the software CLTotal to subsequently construct linear variable-angle trajectories in the spectra, in order to obtain more selective 2D spectra facilitating the simultaneous determination of the analytes. The results of the statistical analysis testify to the usefulness of the proposed method for the intended purpose.

Polycyclic aromatic hydrocarbons in infant formulae, follow-on formulae, and baby foods in Iran: An assessment of risk

Twenty-seven samples of infant formulae and follow-on formulae and fifteen samples of baby food from Iranian markets were analyzed for concentrations of four polycyclic aromatic hydrocarbons (PAH4) determined by use of gas chromatography coupled to mass spectrophotometry. An assessment of risks posed to infants and toddlers was conducted by calculating the margin of exposure and incremental lifetime cancer risk (ILCR) by use of the Monte Carlo Simulation Method. Benzo (a) anthracene, was not detected in any of the samples, while approximately 64.3% samples contained detectable amounts of benzo (a) pyrene, while chrysene was observed in three samples and benzo (b) fluoranthene was detected in one sample. One of the samples contained 1.43 μg PAH4/kg, which was greater than the maximum tolerable limit (MTL; 1 μg/kg) stated in Commission Regulation (EU) 2015/1125. Accordingly, the 95% ILCRs in the infants/toddlers due to ingestion of milk powder and baby foods were determined to be 1.3 × 10^-6 and 7.3 × 10^-7, respectively. Also, the 95th centiles of the MOEs, due to ingesting milk powder or baby foods by infants/toddlers were estimated to be 3.6 × 10⁴ and 7.2 × 10⁴, respectively. In Iran, infants and toddlers are not at serious health risk (MOE ≥ 1 × 10⁴ and ILCR < 1 × 10^-4).

The role of organic matter and clay content in sediments for bioavailability of pyrene

Evaluation of the bioavailable fractions of organic contaminants such as polycyclic aromatic hydrocarbons (PAHs) is extremely important for assessing their risk to the environment. This available fraction, which can be solubilised and/or easily extracted, is believed to be the most accessible for bioaccumulation, biosorption and/or transformation. Sediment organic matter (OM) and clay play an important role in the biodegradation and bioavailability of PAHs. The strong association of PAHs with OM and clay in sediments has a great influence not only on their distribution but also on their long-term environmental impact. This paper investigates correlations between bioavailability and the clay and OM contents in sediments. The results show that OM is a better sorbent for pyrene (chosen as a model PAH) and that increasing the OM content reduces the bioavailable fraction. A mathematical model was used to predict the kinetic desorption, and these results showed that the sediment with the lowest content of OM had an F_fast value of 24%, whereas sediment with 20% OM gave a value of 9%. In the experiments with sediments with different clay contents, no clear dependence between clay and rate constants of the fast desorbing fractions was observed, which can be explained by the numerous possible interactions at the molecular level.

Investigation of ethyl lactate as a green solvent for desorption of total petroleum hydrocarbons (TPH) from contaminated soil

Treatment of oil-contaminated soil is a major environmental concern worldwide. The aim of this study is to examine the applicability of a green solvent, ethyl lactate (EL), in desorption of diesel aliphatic fraction within total petroleum hydrocarbons (TPH) in contaminated soil and to determine the associated desorption kinetics. Batch desorption experiments were carried out on artificially contaminated soil at different EL solvent percentages (%). In analysing the diesel range of TPH, TPH was divided into three fractions and the effect of solvent extraction on each fraction was examined. The experimental results demonstrated that EL has a high and fast desorbing power. Pseudo-second order rate equation described the experimental desorption kinetics data well with correlation coefficient values, R ², between 0.9219 and 0.9999. The effects of EL percentage, initial contamination level of soil and liquid to solid ratio (L/S (v/w)) on initial desorption rate have also been evaluated. The effective desorption performance of ethyl lactate shows its potential as a removal agent for remediation of TPH-contaminated soil worldwide.

The total and freely dissolved polycyclic aromatic hydrocarbons content in residues from biogas production

In the situation of increasing agricultural utilization of residues from biogas production (RBP) it is important to determine the concentration of contaminants, which could occur in these materials. The group of contaminants that requires special attention are polycyclic aromatic hydrocarbons (PAH). The objective of the study was to determine the total and freely dissolved (Cfree) of PAHs in RBP from 6 different biogas plants operating under various temperature conditions and without or with the separation into the solid and liquid fractions. The freely dissolved PAHs were determined using polyoxymethylene (POM method). The total content of the Σ16 PAHs in RBP varied from 449 to 6147 μg/kgdw, while that of Cfree PAHs was at the level from 57 to 653 ng/L. No significant differences were noted in the content of the Σ16 PAHs (total) between the solid and the liquid fractions. This indicates that in the course of the separation, the PAHs are distributed proportionally between the fractions. However in the case of Cfree, PAHs content in the solid fraction was over twice as high as in the liquid fraction. This was probably due to the greater affinity of the particles present in the liquid fraction to the analysed PAHs than to the particles of the solid fraction. Higher affinity to liquid fraction was also confirmed by the distribution coefficients KTOC determined on the basis of Cfree.

Use of physiologically-based pharmacokinetic modeling to simulate the profiles of 3-hydroxybenzo(a)pyrene in workers exposed to polycyclic aromatic hydrocarbons

Biomathematical modeling has become an important tool to assess xenobiotic exposure in humans. In the present study, we have used a human physiologically-based pharmacokinetic (PBPK) model and an simple compartmental toxicokinetic model of benzo(a)pyrene (BaP) kinetics and its 3-hydroxybenzo(a)pyrene (3-OHBaP) metabolite to reproduce the time-course of this biomarker of exposure in the urine of industrially exposed workers and in turn predict the most plausible exposure scenarios. The models were constructed from in vivo experimental data in rats and then extrapolated from animals to humans after assessing and adjusting the most sensitive model parameters as well as species specific physiological parameters. Repeated urinary voids from workers exposed to polycyclic aromatic hydrocarbons (PAHs) have been collected over the course of a typical workweek and during subsequent days off work; urinary concentrations of 3-OHBaP were then determined. Based on the information obtained for each worker (BaP air concentration, daily shift hours, tasks, protective equipment), the time courses of 3-OHBaP in the urine of the different workers have been simulated using the PBPK and toxicokinetic models, considering the various possible exposure routes, oral, dermal and inhalation. Both models were equally able to closely reproduce the observed time course of 3-OHBaP in the urine of workers and predicted similar exposure scenarios. Simulations of various scenarios suggest that the workers under study were exposed mainly by the dermal route. Comparison of measured air concentration levels of BaP with simulated values needed to obtain a good approximation of observed time course further pointed out that inhalation was not the main route of exposure for most of the studied workers. Both kinetic models appear as a useful tool to interpret biomonitoring data of PAH exposure on the basis of 3-OHBaP levels.

Residues of organochlorine pesticides and polycyclic aromatic hydrocarbons in farm-raised livestock feeds and manures in Jiangsu, China

The residual levels of 8 organochlorine pesticides (OCPs) and 15 priority polycyclic aromatic hydrocarbons (PAHs) were determined in pig, chicken, and cow feed and manure samples collected from feedlots in Jiangsu province, China. The mean residuals of OCPs ranged from 25.35 to 65.62 ng g(-1) in feeds and from 33.46 to 90.89 ng g(-1) in manures. Among 4 hexachlorocyclohexanes (HCHs), α-HCH was the most abundant compound, with a high occurrence above 80% in all kinds of animal feeds and manures. For dichlorodiphenyltrichloroethanes (DDTs), the predominance of p,p'-DDE and p,p'-DDT of total DDTs was also clearly observed. Composite profiles of HCHs and DDTs in feeds indicated that the residuals of lindane and DDTs could be attributed to new inputs in the past several years. The mean residuals of all of the PAHs varied from 128.94 to 389.66 ng g(-1) in manures. The mean concentrations of seven carcinogenic PAHs in manures varied from 16.80 to 79.70 ng g(-1). Of the 15 priority PAHs, phenanthrene was the most dominant PAH species and accounted for approximately 50% of the total PAHs in all animal manures. The distribution of PAHs with different rings showed that PAHs with 3 rings were the primary components in the tested manures.

Levels and distribution of organochlorine pesticides (OCPs) and polycyclic aromatic hydrocarbons (PAHs) in topsoils from SE Romania

The aim of this work was to determine the concentrations of organochlorine pesticides (OCPs) and polycyclic aromatic hydrocarbons (PAHs) in topsoils (n=17) at two sampling depths in Southeastern Romania, including industrial (Galati iron and steel plant) and agricultural sites in Galati and Braila counties, as well as nature reserves such as Lower Prut Meadow (Galati County) and Bugeac Lake (Constanta County), and to compare them with national guidelines and values reported for other regions. The total detectable OCP concentrations vary in the ranges 58-1662ngg(-1) dry weight (dw) for 0-5cm depth and 6-12,644ngg(-1) dw for 5-20cm depth. Of these, the concentrations of HCHs, DDTs, and heptachlor varied in the ranges 6-6818ngg(-1), 27-5826ngg(-1), and 108-873ngg(-1) dw, respectively, the highest values being registered near a cultivated area, located in the proximity of Siret River and Galati town, probably due to extensive use of pesticides in the past. Chlordane was detected only at one industrial site in Galati (53ngg(-1) dw), while the levels of aldrin, dieldrin, endrin and mirex were below the detection limits in all the locations and for both depths. The total PAH concentrations for 5-20cm depth range from 9ngg(-1) (Lower Prut Meadow) to 25,352ngg(-1) dw (cattle farm), being lower than those reported for the upper 5cm layer. The PAH distribution pattern in this study is in agreement with that previously obtained for surface soils from Lower Prut Meadow (prevalence of 3-ring PAHs), industrial area and farmland (prevalence of 4- and 5-ring PAHs), their sources being industrial activity, traffic and agricultural waste burning. Carcinogenic PAHs contribute 44.8-56.4% for 5-20cm and 43.7-55.8% for 0-5cm depth to total PAHs. In some locations the HCH, DDT and PAH amounts exceed the legal values.