Incomplete combustion of solid fuels (animal dung and bituminous coal) is a common phenomenon during residential cooking and heating in the Qinghai-Tibetan Plateau (QTP), resulting in large amounts of pollutants emitted into the atmosphere. This study investigated the pollutant emissions from six burning scenarios (heating and cooking with each of the three different fuels: yak dung, sheep dung, and bitumite) in the QTP's pastoral dwellings. Target pollutants such as carbon monoxide (CO), gas-phase polycyclic aromatic hydrocarbons (PAHs), volatile organic compounds (VOCs), fine particles (PM₂.₅, particulate matter with an aerodynamic diameter < 2.5 μm), carbonaceous aerosols, water-soluble ions, and particle-phase PAHs were investigated. Emission factors (EFs) (mean ± standard deviation) of PM₂.₅ from the six scenarios were in the range of 1.21 ± 0.47–7.03 ± 1.95 g kg⁻¹, of which over 60% mass fractions were carbonaceous aerosols. The ratio of organic carbon to elemental carbon ranged from 9.6 ± 2.7–33.4 ± 11.5 and 81.7 ± 30.4–91.9 ± 29.0 for dung and bitumite burning, respectively. These values were much larger than those reported in the literature, likely because of the region's high altitudes—where the oxygen level is approximately 65% of that at the sea level—thus providing a deficient air supply to stoves. However, the toxicity and carcinogenicity of PAHs emitted from solid fuel combustion in the QTP are significant, despite a slightly lower benzo(a)pyrene-equivalent carcinogenic potency (Bapₑq) in this study than in the literature. The gas-to-particle partitioning coefficient of PAHs and VOC emission profiles in the QTP differed significantly from those reported for other regions in the literature. More attention should be paid to the emissions of PAH derivatives (oxygenated PAHs and nitro-PAHs), considering their enhanced light-absorbing ability and high BaPₑq from solid fuel combustion in the QTP.

Persistent organic pollutants (POPs) including PCDD/Fs, PCBs and organochlorine pesticides (OCPs) are among the most important and hazardous pollutants of soil. Food producing animals such as chicken, beef, sheep and goats can take up soil while grazing or living outdoors (free-range) and this can result in contamination.In recent decades, large quantities of brominated flame retardants such as polybrominated diphenyl ethers (PBDEs), short-chain chlorinated paraffins (SCCPs) and per- and polyfluorinated alkylated substances (PFAS) have been produced and released into the environment and this has resulted in widespread contamination of soils and other environmental matrices. These POPs also bioaccumulate and can contaminate food of animal origin resulting in indirect exposure of humans.Recent assessments of chicken and beef have shown that surprisingly low concentrations of PCBs and PCDD/Fs in soil can result in exceedances of regulatory limits in food. Soil contamination limits have been established in a number of countries for PCDD/Fs but it has been shown that the contamination levels which result in regulatory limits in food (the maximum levels in the European Union) being exceeded, are below all the existing soil regulatory limits. ‘Safe’ soil levels are exceeded in many areas around emission sources of PCDD/Fs and PCBs. On the other hand, PCDD/F and dioxin-like PCB levels in soil in rural areas, without a contamination source, are normally safe for food producing animals housed outdoors resulting in healthy food (e.g. meat, eggs, milk).For the majority of POPs (e.g. PBDEs, PFOS, PFOA, SCCP) no regulatory limits in soils exist.There is, therefore, an urgent need to develop appropriate and protective soil standards minimising human exposure from food producing animals housed outdoors. Furthermore, there is an urgent need to eliminate POPs pollution sources for soils and to control, secure and remediate contaminated sites and reservoirs, in order to reduce exposure and guarantee food safety.

Antibiotic resistance is an increasingly important environmental pollutant with direct consequences for human health. Identification of environmental sources of antibiotic resistance genes (ARGs) makes it possible to follow their evolution and prevent their entry into the clinical setting. ARGs have been found in environmental sources exogenous to the original source and previous studies have shown that these genes are capable of being transferred from livestock to humans. Due to the nature of farming and the slaughter of ruminants for food, humans interact with these animals in close proximity, and for this reason it is important to consider the risks to human health. In this study, we characterised the ARG populations in the ovine rumen, termed the resistome. This was done using the Comprehensive Antibiotic Resistance Database (CARD) to identify the presence of genes conferring resistance to antibiotics within the rumen. Genes were successfully mapped to those that confer resistance to a total of 30 different antibiotics. Daptomycin was identified as the most common antibiotic for which resistance is present, suggesting that ruminants may be a source of daptomycin ARGs. Colistin resistance, conferred by the gene pmrE, was also found to be present within all samples, with an average abundance of 800 counts. Due to the high abundance of some ARGs (against daptomycin) and the presence of rare ARGs (against colistin), we suggest further study and monitoring of the rumen resistome as a possible source of clinically relevant ARGs.

The effects of Pb pollution on cattle and sheep raised in an ancient mining area were studied through the use of blood Pb (PbB) levels and δ-aminolevulinic acid dehydratase (δ-ALAD) activity. Lead levels in livestock blood from the mining area (n=110) were significantly elevated when compared to the controls (n=79). In 91.4% of cattle (n=58) and 13.5% of sheep (n=52) sampled in the mining area, PbB levels corresponded to subclinical exposure (6–35μg/dl). Two young cattle (<2 years) from the mining area (n=5) had PbB levels indicative of clinical poisoning (>35μg/dl). Elevated PbB was also accompanied by δ-ALAD activity inhibition in blood, which confirms that measurable effects of Pb poisoning were taking place. Observed PbB levels suggest that a potential risk to human consumers of beef from the Pb polluted areas may also exist, as has been shown previously for game meat from the same mining area.

This study examined arsenite [As(III)], arsenate [As(V)] and fluoride (F⁻) removal potential of bone char produced from sheep (Ovis aries) bone waste. Pyrolysis conditions tested were in the 500 °C–900 °C range, for a holding time of 1 or 2 h, with or without N₂ gas purging. Previous bone char studies mainly focused on either low or high temperature range with limited information provided on As(III) removal. This study aims to address these gaps and provide insights into the effect of pyrolysis conditions on bone char sorption capacity. A range of advanced chemical analyses were employed to track the change in bone char properties. As pyrolysis temperature and holding time increased, the resulting pH, surface charge, surface roughness, crystallinity, pore size and CEC all increased, accompanied by a decrease in the acidic functional groups and surface area. Pyrolysis temperature was a key parameter, showing improvement in the removal of both As(III) and As(V) as pyrolysis temperature was increased, while As(V) removal was higher than As(III) removal overall. F⁻ removal displayed an inverse relationship with increasing pyrolysis temperature. Bone char prepared at 500 °C released significantly more dissolved organic carbon (DOC) then those prepared at a higher temperature. The bone protein is believed to be a major factor. The predominant removal mechanisms for As were surface complexation, precipitation and interaction with nitrogenous functional groups. Whereas F⁻ removal was mainly influenced by interaction with oxygen functional groups and electrostatic interaction. This study recommends that the bone char pyrolysis temperature used for As and F⁻ removal are 900 °C and 650 °C, respectively.

Genome fragment enrichment (GFE) method was applied to identify host-specific bacterial genetic markers that differ among different fecal metagenomes. To enrich for swine-specific DNA fragments, swine fecal DNA composite (n = 34) was challenged against a DNA composite consisting of cow, human, goat, sheep, chicken, duck and goose fecal DNA extracts (n = 83). Bioinformatic analyses of 384 non-redundant swine enriched metagenomic sequences indicated a preponderance of Bacteroidales-like regions predicted to encode metabolism-associated, cellular processes and information storage and processing. After challenged against fecal DNA extracted from different animal sources, four sequences from the clone libraries targeting two Bacteroidales- (genes 1–38 and 3–53), a Clostridia- (gene 2–109) as well as a Bacilli-like sequence (gene 2–95), respectively, showed high specificity to swine feces based on PCR analysis. Host-specificity and host-sensitivity analysis confirmed that oligonucleotide primers and probes capable of annealing to select Bacteroidales-like sequences (1–38 and 3–53) exhibited high specificity (>90%) in quantitative PCR assays with 71 fecal DNAs from non-target animal sources. The two assays also demonstrated broad distributions of corresponding genetic markers (>94% positive) among 72 swine feces. After evaluation with environmental water samples from different areas, swine-targeted assays based on two Bacteroidales-like GFE sequences appear to be suitable quantitative tracing tools for swine fecal pollution.

Nairobi city in Kenya produces 2000 tons/day of garbage, and most of it is dumped onto the Dandora dumping site, home to a quarter-million residents. This study was conducted (1) to assess the contamination levels of nine metals and a metalloid (arsenic) in the blood of pigs, goats, sheep and cattle from Dandora, and (2) to identify a possible source of lead (Pb) pollution. Cadmium (Cd, 0.17–4.35 μg/kg, dry-wt) and Pb (90–2710 μg/kg) levels in blood were generally high, suggesting human exposure to Cd through livestock consumption and Pb poisoning among pigs (2600 μg/kg) and cattle (354 μg/kg). Results of Pb isotope ratios indicated that the major exposure route might differ among species. Our results also suggested a possibility that the residents in Dandora have been exposed to the metals through livestock consumption.

To determine if current sheep/beef farming practices affect pesticide residues in streams, current-use and legacy chlorinated pesticides were quantified in 100 sediment samples from 15 streams on the South Island of New Zealand. The study involved five blocks of three neighboring farms, with each block containing farms managed by organic, integrated and conventional farming practices. Significantly higher concentrations of dieldrin, ∑ endosulfans, ∑ current-use pesticides, and ∑ chlorinated pesticides were measured in sediments from conventional farms compared to organic and integrated farms. However, streams in the latter two farming categories were not pesticide-free and sometimes contained relatively high concentrations of legacy pesticides. Comparison of measured pesticide concentrations with sediment quality guidelines showed that, regardless of farming practice, mean pesticide concentrations were below the recommended toxicity thresholds. However, up to 23% of individual samples contained chlorpyrifos, endosulfan sulfate, ∑ DDT, dieldrin, or ∑ chlordane concentrations above these thresholds.

Muscle tissue was collected from ewes and lambs derived from farms throughout Scotland and sample concentrations of five endocrine disrupting compound groups were determined. Farms of origin were categorised according to geographic region. There were few statistically-significant differences with region or distance from cities. However, the magnitude of the difference between the highest and lowest mean values in ewe muscle from different regions exceeded 30% for 13 of the 15 compounds that were consistently detected in muscle, with animals derived from the industrialised region having the highest mean values for 11 of the 13 compounds. A less marked trend was apparent in the lamb muscle (8 of 13 highest were in the industrialised region). The physiological effects of such small differences in exposure to mixtures of pollutants remain to be determined.

Dufulin is a biologically derived antiviral agent chemically synthesized by α-phosphoramidate in sheep and is effective against viral diseases in plants such as tobacco, rice, cucumber and tomato. However, the environmental behaviors and fate of Dufulin under different cultivation systems remain unknown. This study investigates the absorption, translocation and accumulation of ¹⁴C-Dufulin stereoisomers introduced by pesticide leaf daubing and by mixing the pesticide with soil in different tissues of cherry radish. We particularly focused on whether the behaviors of Dufulin enantiomers in plants were stereoselective. In the leaf uptake experiments, S-Dufulin and R-Dufulin were transported both up and down, while more than 93% of the pesticide remained in the labeled leaves. During the radicular absorption experiments, both enantiomers of Dufulin were taken up by radish roots and moved to the upper part of the plant, while less than 0.2% Dufulin was absorbed from the soil. Hence, it was easier for Dufulin to enter plants through the leaf surface than through the roots. However, we found in this trial that the stereoisomers of Dufulin underwent nonstereoselective absorption and translocation, which implies that rac-Dufulin and its metabolites should be a major research priority. Overall, our results provide a relatively accurate prediction of the risk assessment of Dufulin, which will help guide its rational use in the environment as well as ensure eco-environmental safety and human health.