Mutagenicity of particulates from the laboratory combustion of plastics

Vegan leather: a sustainable reality or a marketing gimmick?

The textile industry is the only one which has utilised all kinds of resources available in nature, and the evolution of textile materials has drastically hampered nature as well. Leather and fur are a few of the classic examples of materials derived from animals that have attracted dialogues about animal rights and ethical sourcing. To substitute animal-based leather, numerous materials have been manufactured synthetically and semi-synthetically. This review article discusses various types of leather, viz., bovine leather, poromerics, leatherette, plant-based vegan leather, and the sustainable alternatives available in the market as well as at the inductive research phase. The article is a comprehensive review of the leather and its commercially available alternatives along with their marketing strategy, and technical details. The article also compiles insight into the processing, and the components of vegan leather and the environmental issues related to them. The sustainability and circularity of processing in manufacturing vegan leather have also been discussed, with biodegradability as the focal point.

Ecotoxicity of PM10 emissions generated during controlled burning of waste PET

Domestic waste is often burned either as fuel for winter heating or in open areas, simply to get rid of waste. Polyethylene terephthalate (PET) represents an important component of plastics usage as well as of plastic waste produced. While most studies attempt to characterize environmental risk of open burning of mixed household waste, present work evaluates chemical and ecotoxicological parameters of particulate matter (PM) produced during controlled burning of PET samples. In the PM₁₀ samples, polycyclic aromatic hydrocarbon and heavy metal concentrations were measured, ecotoxicity was evaluated using the kinetic Vibrio fischeri bioassay. Both chemical composition and ecotoxicity of the 4 samples showed significant correlation, regardless of the colored or colorless nature of the original PET sample. Antimony was found in considerable concentrations, in the range of 6.93-16.9 mg/kg. PAHs profiles of the samples were very similar, showing the dominance of 4-and 5-ring PAHs, including carcinogenic benzo(a)pyrene.

Occurrence and fate of polycyclic aromatic hydrocarbons from electronic waste dismantling activities: A critical review from environmental pollution to human health

Electronic waste (e-waste) is one of the fastest-growing solid wastes and has become an urgent issue due to the potential adverse consequences of exposure to emitted toxic pollutants, especially for these occupational exposed workers and local residents. In this review, the environmental occurrences, emission characteristics, sources, and possible adverse effects of polycyclic aromatic hydrocarbons (PAHs) emitted from primitive e-waste dismantling activities are summarized. In general, the atmospheric levels of PAHs at typical e-waste sites, e.g., in Guiyu, China, have substantially decreased by more than an order of magnitude compared with levels a decade ago. The PAH concentrations in soil from old e-waste sites in China are also generally lower than those at newly emerged e-waste sites in India, Pakistan and Ghana. However, elevated concentrations of PAHs have been reported in human milk, hair and urine from the populations near these e-waste sites. Source apportionment both from bench-scale studies to field observations has demonstrated that the pyrolysis and combustion processing of electronic circuit board are mainly responsible for the emissions of various PAHs. In addition, some specific PAHs and their derivatives, such as triphenylbenzene, halogenated and oxygenated PAHs, have frequently been identified and could be considered as indicators in routine analysis in addition to the 16 U.S. EPA priority PAHs currently used.

Foam dressing incorporating herbal extract: An all-natural dressing for potential use in wound healing

Silk fibroin protein, gastrodia elata, and tea tree oil are naturally derived and have been used throughout human history. This work develops an all-natural and highly porous foam-containing silk fibroin protein and above herbal extract, as a dressing for wound management. Scanning electron microscopic analyses and measurements of porosity by Archimedes method revealed a highly porous structure with porosity ranging from 40%–80%, depending on the preparation condition. In vitro, cytotoxicity test of a series of gastrodia elata–containing silk fibroin protein and tea tree oil–containing silk fibroin protein foam dressings on 3T3 fibroblast cells showed 90%–100% cell viability, which indicated that the produced all-natural dressings have no significant cytotoxicity toward skin cells. In another anti-inflammatory assay using the lipopolysaccharide-induced inflammatory Raw 264.7 macrophages model, the produced two dressings exhibited up to 70% and 90.1% of reduction in the formation of nitrite, in comparison with the untreated group. In vivo studies showed that all herbal extract–containing foam dressings accelerated wound recovery and achieved full closure of the wound within 21 days, and the histological analysis of regenerative skin tissues indicated that the produced foam dressings enhance the generation of thicker, denser, and more abundant collagen fibers in the dermis layer in comparison with the positive and negative control groups.

Toxic emissions from open burning

This review compiled the data from recent actual and simulation studies on toxic emissions from open burning and categorized into sources, broadly as biomass and anthropogenic fuels. Emission factors, in mass of pollutant per mass of material being burned, and actual concentrations, in mass of pollutant per unit volume have been compared based on source classifications. In addition to gaseous emissions, this review presents the updated data on emissions to air in the form of particulate matter, and emissions to soil and water environment. Data from forest fires, accidental fires such as vehicle fires, house fires, and unintentional landfill fires are included in this review as well as combustion involving traditional and recreational activities.

Reaction of nitroso derivatives of dinitropyrenes with sulfhydryl groups of peptides and hemoglobinin vitroand in rats

Diesel engine emissions have been classified as a potential human carcinogen and may cause a variety of other health effects. Human exposure to diesel engine emissions is highly variable within the population. Therefore, specific methods for the biomonitoring of human exposure to diesel engine emissions are required for exposure assessment within epidemiological studies. Haemoglobin adducts of dinitropyrenes may serve as biomarkers for human exposures to diesel engine emissions.To characterize structures of dinitropyrene reaction products with sulfhydryl groups, glutathione was used to trap electrophilic nitroso intermediates formed from dinitropyrenes and glutathione S-conjugates were identified and characterized by Qtrap techniques using (HPLC-MS/MS) high-performance liquid chromatography coupled to triple quadrupole mass spectrometry. Nitrosonitropyrene-derived sulfinamides, sulfenamides and glutathione thioethers bound to carbon atoms in the aromatic ring, presumably formed by a rearrangement of intermediate sulfenamide cations, were formed in low yields. In haemoglobin from rats orally administered dinitropyrenes, mild alkaline hydrolysis of haemoglobin released aminonitropyrenes, which were identified by HPLC-MS/MS. The results demonstrate that dinitropyrenes undergo nitroreduction in rats and that the intermediate nitrosonitropyrenes bind to heamoglobin. The haemoglobin adducts formed from dinitropyrenes seem, in contrast to previous studies, to be hydrolysable and thus represent sulfen- and sulfinamides derived from the intermediate nitrosonitropyrenes. The developed Qtrap methods to detect and characterize glutathione S-conjugates rapidly may have wide applications in attempts to characterize reactive intermediates formed in complex mixtures in low concentrations.

Persistent free radicals, heavy metals and PAHs generated in particulate soot emissions and residue ash from controlled combustion of common types of plastic

The production and use of polymeric materials worldwide has reached levels of 150 million tonnes per year, and the majority of plastic materials are discarded in waste landfills where are burned generating toxic emissions. In the present study we conducted laboratory experiments for batch combustion/burning of commercial polymeric materials, simulating conditions of open fire combustion, with the purpose to analyze their emissions for chemical characteristics of toxicological importance. We used common types of plastic materials: poly(vinyl chloride) (PVC), low and high density poly(ethylene) (LDPE, HDPE), poly(styrene) (PS), poly(propylene) (PP) and poly(ethylene terephthalate) (PET). Samples of particulate smoke (soot) collected on filters and residue solid ash produced by controlled burning conditions at 600-750 degrees C are used for analysis. Emissions of particulate matter, persistent free radicals embedded in the carbonaceous polymeric matrix, heavy metals, other elements and PAHs were determined in both types of samples. Results showed that all plastics burned easily generating charred residue solid ash and black airborne particulate smoke. Persistent carbon- and oxygen-centered radicals, known for their toxic effects in inhalable airborne particles, were detected in both particulate smoke emissions and residue solid ash. Concentrations of heavy metals and other elements (determined by Inductively Coupled Plasma Emission Spectrometry, ICP, method) were measured in the airborne soot and residue ash. Toxic heavy metals, such as Pb, Zn, Cr, Ni, and Cd were relatively at were found at low concentrations. High concentrations were found for some lithophilic elements, such as Na, Ca, Mg, Si and Al in particulate soot and residue solid ash. Measurements of PAHs showed that low molecular weight PAHs were at higher concentrations in the airborne particulate soot than in the residue solid ash for all types of plastic. Higher-ringed PAHs were detected at higher concentrations in the residue solid ash of PVC as compared to those from the other types of plastic. The open-air burning of plastic material and their toxic emissions is of growing concern in areas of municipal solid waste where open-fires occur intentionally or accidentally. Another problem is building fires in which victims may suffer severe smoke inhalation from burning plastic materials in homes and in working places.

Genetic polymorphisms of NAD(P)H quinone oxidoreductase, CYP1A1 and microsomal epoxide hydrolase and lung cancer risk in Nanjing, China

Genetic variations in metabolic activation or detoxification enzymes have been thought to contribute to individual differences in lung cancer susceptibility. Genetic polymorphisms of NAD(P)H quinone oxidoreductase (NQO1), cytochrome P4501A1 (CYP1A1) and microsomal epoxide hydrolase (HYL1) have been associated with increased lung cancer risk in Asian populations. In the present study, the possibility of an association of NQO1, CYP1A1 and HYL1 genetic polymorphisms with lung cancer was examined among residents in Nanjing, China. A total of 84 lung cancer patients and 84 control subjects were matched by age, gender, occupation and smoking status. No significant association was observed for these genetic polymorphisms with the overall incidence of lung cancer. When the groups were stratified according to smoking status, we found that smokers carrying the HYL1*2 allele had a higher relative risk for lung cancer Odds ratio ((OR), 5.66; 95% confidence interval (95% CI), 1.71-18.68). The association was also found with squamous cell carcinoma (OR, 3.23; 95% CI, 1.00-10.38). Our results suggest that HYL1*2 polymorphism might be a risk factor for smoking-associated lung cancer in China.

Chromatographic methods for carcinogenic/mutagenic nitropolycyclic aromatic hydrocarbons

Nitropolycyclic aromatic hydrocarbons (NPAHs), which are known to be carcinogenic and/or mutagenic, are considered to be one of the air pollutants that cause lung cancer. In the last two decades, a number of sensitive and selective methods have been developed for the determination of NPAHs and related compounds in environmental and biological samples. This paper describes the state of the art of the methods and applications.

Distributions of nitropyrenes and mutagenicity in airborne particulates collected with an Andersen sampler

Distributions of 1,3-dinitropyrene (1,3-DNP), 1,6-DNP, 1,8-DNP, 1-nitropyrene (1-NP) and mutagenicity in airborne particulates collected in downtown Kanazawa, Japan with an Andersen high-volume air sampler were examined. Mutagenicities of benzene-ethanol extract from particulates were determined by the Ames test using S. typhimurium strains without S9 mix, while concentrations of DNPs and 1-NP were determined by high-performance liquid chromatography (HPLC) using chemiluminescence detection. In the finest particulate fraction (smaller than 1.1 microns), 68% and 75% of the total mutagenicities were observed in TA98 and YG1024 strains, respectively. In the same fraction, 65-82% of three DNPs as well as 84% of 1-NP were observed. Mutagenic contributions of 1,3-DNP, 1,6-DNP, 1,8-DNP and 1-NP in the extract were respectively 0.6, 1.2, 1.8 and 1.6% in the TA98 strain, and 2.5, 5, 9 and 2.1% in the YG1024 strain.