Polychlorodibenzodioxin and -furan (PCDD and PCDF) and dioxin-like polychlorobiphenyl (DL-PCB) congener levels in milk of grazing sheep as indicators of the environmental quality of rural areas

Occurrence and congener profiles of dioxins (PCDDs), furans (PCDFs) and polychlorinated biphenyls (PCBs) in ovine and caprine milk samples collected in a very polluted site in Central Italy

Concentrations of 7 polychlorinated dibenzo-p-dioxins (PCDDs), 10 polychlorinated dibenzofurans (PCDFs) and 18 polychlorinated biphenyls (PCBs), including 12 dioxin-like (DL-PCBs) and 6 non-dioxin-like PCBs (NDL-PCBs) were measured in 16 ovine and caprine milk samples collected in the territory of Bussi sul Tirino, central Italy, a Site of National Interest (SNI) due to its high and widespread environmental pollution. All the analyzed samples were compliant with the maximum levels fixed by Commission Regulation (EU) 1259/2011 for the content of PCDD/Fs and the sum of PCDD/Fs and DL-PCBs. In two cases, contamination levels of the sum of PCDD/Fs and DL-PCBs were higher than the action levels fixed by EU Recommendation 663/2014. The statistical analysis, performed by Principal Component Analysis (PCA), revealed that the differences in contamination profiles of the different milk samples were independent of the distance of the farms from the Bussi illegal landfill but likely related to local emission sources influencing the exposure to POPs of studied animals.

A retrospective study on dioxins and dioxin-like polychlorinated biphenyls in milk and dairy products from the Latium region (Italy) over a 7-year study period (2011-2017)

This study reports the data of polychlorinated dibenzo-p-dioxins (PCDDs), -furans (PCDFs), and polychlorinated biphenyls dioxin-like (dl PCBs) measured in a total of 260 samples of the dairy supply chain collected over a period of 7 years (2011-2017) in the Latium region (Italy). Levels and average profiles of congeners were reported for each group of the analyzed dairy matrices, and any differences between different sampling strategies were considered (around likely pollutant sources or casual sampling). Of the samples, 95.4% resulted compliant with the regulated levels; only samples belonging to the "sheep bulk milk" matrix were found to be above either the action levels or the maximum levels (tot. 12 samples). Raw milk of the sheep species showed the highest averages (PCDD/F 0.248 and dl PCB 0.966 WHO TEQ pg/g of fat) compared to the milk of other species. The buffalo milk showed a content of dl PCB significantly lower (dl PCB: 0.371 WHO TEQ pg/g of fat) than the sheep milk (p<0.05). Dioxins were found to be superior to furans in almost all dairy products, except in the noncompliant samples where furans were higher. The OCDD was found to be the most abundant congener in almost all dairy products. This study provides a first list of reference values for background contamination of the dairy supply chain in the Latium region. These pre-existing values will be useful in all cases of environmental pollution to identify critical situations.

Organic farming: Does it contribute to contaminant-free produce and ensure food safety?

Organic farming for higher ecological and human health benefits has been adopted in about 186 countries, covering a total area of 71.5 Mha worldwide. Because of the associated practices, the flows of several environmental pollutants into the organic products threaten food safety and human health. The contaminants that occur at higher concentrations in organic produce include persistent organic pollutants (61.3-436.9 ng g^-1 lamb meat, and 0.28 pg g^-1-2.75 ng g^-1 bovine meat), heavy metals (0.5-33.0 mg kg^-1 lettuce), organochlorine pesticides (11-199 μg g^-1 carrots), cyclodienes, hexachlorocyclohexanes, hexabromocyclododecane (2-3 times higher than in conventionally produced porcine meat), hexachlorobenzene (1.38-14.49 ng g^-1 fat in milk), and non-brominated flame retardants (1.3-3.2 times higher than in conventional produce of greenhouse-grown tomato and cucumber). Moreover, some pollutants like per- and polyfluoroalkyl substances with a longer half-life (1.50-9.10 yrs) are reported to occur in several organic products. In fact, several legacy persistent organic pollutants are known for their significant trophic magnification in an urban terrestrial ecosystem. In addition, many plant functionalities are adversely affected in organic farming. Therefore, the long-term usage of organic products containing such pollutants poses a significant threat to human health. The major limitation in organic livestock production is the severe shortage of organic feed. Several variable standards and technical regulations set by the government and private agencies are the major obstacles in the global marketing of organic products. The present review critically addresses the impact of organic farming on hidden risks due to the use of composts as the amendment resources that enhance the phytoaccumulation and trophic transfer of pollutants, the functional diversity of the ecosystems, and poor harmonization among the policies and regulations in different countries for organic farming. The future directions of research have been suggested to mitigate unintended flows of pollutants into the organic products.

Environmental status of an Italian site highly polluted by illegal dumping of industrial wastes: The situation 15 years after the judicial intervention

In 2008 the Italian government classified the Bussi sul Tirino area (Central Italy) as Site of National Interest destined to remediation which, unfortunately, has not yet begun. The decision followed >20 years of illegal dumping of industrial wastes, lasting from 1984 to 2005, that generated the biggest illegal toxic waste disposal site in Europe. The contamination profile of the site was mainly characterized by PCDD/Fs, PCBs, PAHs, chlorinated solvents, Hg, and Pb. Due to the health concern of the population and local authorities, an extensive monitoring and biomonitoring campaign was carried out in 2017-2018, checking the site-specific pollutants in local food (free-range hens' eggs, milk from grazing sheep and goats, wild edible mushrooms, and drinking water), environmental (air and freshwaters) and biological (human urine) matrices. A total of 314 samples were processed, obtaining 3217 analytical data that were compared with regulatory limits, when available, and values reported by international literature. The sum PCDD/Fs and DL-PCBs ranged from 0.24 to 3.6 pg TEQ g^-1 fat, and from 0.46 to 8.3 pg TEQ g^-1 fat, respectively in milk in eggs, in line with the maximum levels established by CE Regulations except for an egg sample. As regards PAHs, all our results were lower than the literature data, as well as for Hg and Pb. Outdoor air showed levels of chlorinated solvents ranging from <LOD to 36 μg m^-3, and freshwaters from 0.21 to 2.8 μg L^-1. All drinking water samples resulted compliant with the maximum levels established by the current EU directive. Despite the severe pollution of the illegal dumping site and the remediation not yet carried out, the local environment and the population living in Bussi and surroundings seem not to be affected by significant exposure to the toxics characterizing the landfill.

Application of a risk-based standardized animal biomonitoring approach to contaminated sites

Biomonitoring has been used to disclose the public health impact of contaminated sites. This study aimed at setting up good practices to apply biomonitoring targeting animal matrixes to design risk-based surveillance and exposure assessment plans. A nine-step protocol targeting farmed animals was devised and tested in three case study areas including (1) a waste dump, (2) a waste incinerator, and (3) a secondary aluminum smelter. Between 2010 and 2012, in each study area, the following 9-step best practices were applied: hazard identification, GIS project creation, risk area delimitation, control area selection, receptors (livestock) identification, farms and matrixes selection, sampling study design, on-farm secondary sources exclusion, and statistical and geostatistical analysis. Dairy farms and free-range laying hens were the primary targets: eggs from both risk and control areas and milk from risk areas were sampled and submitted for detection of selected tracking contaminants compatible with the putative sources. Comparison data (risk vs. control) of heavy metal concentrations in eggs were available only for case study 2, whereas egg comparison data of persistent organic pollutants were available for all the risk-control pairs. After taking into account potential secondary sources, no concern from metals was arisen, whereas high concentrations of persistent organic pollutants were detected in all risk areas; however, only for the aluminum smelter case study, the contamination was broad and higher in the risk area compared with the control one. The protocol has proved to be easily applicable and flexible to varying contexts and able to provide helpful data to inform risk management decisions.

Occurrence of environmental pollutants in foodstuffs: A review of organic vs. conventional food

In recent years, there is an increasing trend to consume organic foods instead of the conventional foodstuffs. This tendency is mainly due to the concern raised by the potential adverse health effects derived from the intake of pesticides, fertilizers, hormones and antibiotics, which are widely used in regular food production. Although organic label forbids the use of these products, environmental contamination is likely to occur in both, conventional and organic foodstuffs. The main purpose of this review was to compare the levels of a number of environmental pollutants such as polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs), mycotoxins, trace elements, polycyclic aromatic hydrocarbons (PAHs), etc., in organic and conventional food items. The results show that, in general, the presence of nearby anthropogenic sources of pollution is the key issue influencing the occurrence of environmental pollutants in foodstuffs, regardless their organic or conventional origin. Based on this, we suggest that environmental contaminants should be monitored in both conventional and organic foods. Finally, the safety feature, which has been globally attributed to organic foods, might be questionable depending on the potential environmental contamination of these foods.

Comparative analysis of metagenomes of Italian top soil improvers

Biosolids originating from Municipal Waste Water Treatment Plants are proposed as top soil improvers (TSI) for their beneficial input of organic carbon on agriculture lands. Their use to amend soil is controversial, as it may lead to the presence of emerging hazards of anthropogenic or animal origin in the environment devoted to food production. In this study, we used a shotgun metagenomics sequencing as a tool to perform a characterization of the hazards related with the TSIs. The samples showed the presence of many virulence genes associated to different diarrheagenic E. coli pathotypes as well as of different antimicrobial resistance-associated genes. The genes conferring resistance to Fluoroquinolones was the most relevant class of antimicrobial resistance genes observed in all the samples tested. To a lesser extent traits associated with the resistance to Methicillin in Staphylococci and genes conferring resistance to Streptothricin, Fosfomycin and Vancomycin were also identified. The most represented metal resistance genes were cobalt-zinc-cadmium related, accounting for 15-50% of the sequence reads in the different metagenomes out of the total number of those mapping on the class of resistance to compounds determinants. Moreover the taxonomic analysis performed by comparing compost-based samples and biosolids derived from municipal sewage-sludges treatments divided the samples into separate populations, based on the microbiota composition. The results confirm that the metagenomics is efficient to detect genomic traits associated with pathogens and antimicrobial resistance in complex matrices and this approach can be efficiently used for the traceability of TSI samples using the microorganisms' profiles as indicators of their origin.

Quantification of Polychlorinated Biphenyls and Polybrominated Diphenyl Ethers in Commercial Cows' Milk from California by Gas Chromatography-Triple Quadruple Mass Spectrometry

We determined 12 polybrominated diphenyl ethers (PBDEs) and 19 polychlorinated biphenyls (PCBs) congeners in eight different brands of commercial whole milk (WM) and fat free milk (FFM) produced and distributed in California. Congeners were extracted using a modified quick, easy, cheap, effective, rugged and safe (QuEChERS) method, purified by gel permeation chromatography, and quantified using gas chromatography-triple quadruple mass spectrometry. PBDEs and PCBs were detected in all FFM and WM samples. The most prevalent PBDE congeners in WM were BDE-47 (geometric mean: 18.0 pg/mL, 0.51 ng/g lipid), BDE-99 (geometric mean: 9.9 pg/mL, 0.28 ng/g lipid), and BDE-49 (geometric mean: 6.0 pg/mL, 0.17 ng/g lipid). The dominant PCB congeners in WM were PCB-101(geometric mean: 23.6 pg/mL, 0.67 ng/g lipid), PCB-118 (geometric mean: 25.2 pg/mL, 0.72 ng/g lipid), and PCB-138 (geometric mean: 25.3 pg/mL, 0.72 ng/g lipid). The sum of all 19 PCB congeners in FFM and WM were several orders of magnitude below the U.S. FDA tolerance. The sum of PBDEs in milk samples suggest close proximity to industrial emissions, and confirm previous findings of elevated PBDE levels in California compared to other regions in the United States.

Polychlorodibenzodioxin and -furan and dioxin-like polychlorobiphenyl distribution in tissues and dairy products of dairy buffaloes

A pilot study was performed on three different dairy buffalo herds exposed without exposure control conditions to Polychlorodibenzodioxins and -furans (PCDDs, PCDFs) and Dioxin-like Polychlorobiphenyls (DL-PCBs). This study dealt with the relationship between the contamination levels (pg WHO₂₀₀₅-TE/g fat) in individual raw milk and those in edible tissues and with the contamination transfer from farm bulk milk to dairy products. On a cumulative basis, kidney (41, 67, and 21 pg WHO-TE/g fat) resulted more in equilibrium with milk (48, 42, and 20) than did muscle (25, 31, and 9), while liver showed a large bioaccumulation (221, 304, and 75), with marked differences of the congener profile. Mozzarella cheese contamination (23, 42, and 29 pg WHO-TE/g fat) was higher than that of bulk milk (20, 36, and 21), which suggested a role of casein precipitation in congener transfer. The above information could improve the effectiveness of risk management during a "dioxin" crisis.