Ecotoxicological assessment of oil-based paint using three-dimensional multi-species bio-testing model: pre- and post-bioremediation analysis.

The present study validates the oil-based paint bioremediation potential of Bacillus subtilis NAP1 for ecotoxicological assessment using a three-dimensional multi-species bio-testing model. The model included bioassays to determine phytotoxic effect, cytotoxic effect, and antimicrobial effect of oil-based paint. Additionally, the antioxidant activity of pre- and post-bioremediation samples was also detected to confirm its detoxification. Although, the pre-bioremediation samples of oil-based paint displayed significant toxicity against all the life forms. However, post-bioremediation, the cytotoxic effect against Artemia salina revealed substantial detoxification of oil-based paint with LD50 of 121 µl ml-1 (without glucose) and > 400 µl ml-1 (with glucose). Similarly, the reduction in toxicity against Raphanus raphanistrum seeds germination (%FG = 98 to 100%) was also evident of successful detoxification under experimental conditions. Moreover, the toxicity against test bacterial strains and fungal strains was completely removed after bioremediation. In addition, the post-bioremediation samples showed reduced antioxidant activities (% scavenging = 23.5 ± 0.35 and 28.9 ± 2.7) without and with glucose, respectively. Convincingly, the present multi-species bio-testing model in addition to antioxidant studies could be suggested as a validation tool for bioremediation experiments, especially for middle and low-income countries. Graphical abstract ᅟ.

Toxicity of nanoparticles embedded in paints compared to pristine nanoparticles, in vitro study.

The unique physicochemical properties of nanomaterials has led to an increased use in the paint and coating industry. In this study, the in vitro toxicity of three pristine ENPs (TiO2, Ag and SiO2), three aged paints containing ENPs (TiO2, Ag and SiO2) and control paints without ENPs were compared. In a first experiment, cytotoxicity was assessed using a biculture consisting of human bronchial epithelial (16HBE14o-) cells and human monocytic cells (THP-1) to determine subtoxic concentrations. In a second experiment, a new coculture model of the lung-blood barrier consisting of 16HBE14o- cells, THP-1 and human lung microvascular endothelial cells (HLMVEC) was used to study pulmonary and extrapulmonary toxicity. The results show that the pristine TiO2 and Ag ENPs have some cytotoxic effects at relative high dose, while pristine SiO2 ENPs and all aged paints with ENPs and control paints do not. In the complex triculture model of the lung-blood barrier, no considerable changes were observed after exposure to subtoxic concentration of the different pristine ENPs and paint particles. In conclusion, we demonstrated that although pristine ENPs show some toxic effects, no significant toxicological effects were observed when they were embedded in a complex paint matrix.

Studying the effect of antioxidants on cytogenetic manifestations of solvent exposure in the paint industry.

OBJECTIVE: To investigate the antioxidant role in reversing cytogenetic changes caused by solvent exposure in paint industry. SUBJECTS AND METHODS: A prospective controlled clinical trial was performed on 39 workers exposed to solvents and 39 workers not exposed to solvents by supplying a mixture of antioxidant vitamins (A, C, E and selenium) and the after effects of such regimen were analyzed. Environmental monitoring was carried out for air concentrations of different solvents at workplace. Exposed group was cytogenetically tested before and after giving the mixture of antioxidant vitamins for 1 month duration. RESULTS: Frequency of chromosomal aberrations (CAs) and the mean of sister chromatid exchanges (SCEs) were statistically significantly higher among exposed workers than among controls. After the supplementation of antioxidants, there was a statistically significant decrease in the frequency of CAs, and 88% abnormal levels of SCEs were back to normal levels. CONCLUSION: Antioxidant supplementation decreases the frequency of CAs and SCEs among exposed workers.

Hazardous properties of paint residues from the furniture industry.

The objective of this study was to screen nine excess paint residues for environmental hazard and to evaluate their disposability in a non-hazardous or hazardous-waste landfill. These residues were produced in the process of spray-painting furniture. Residues were classified according to their leaching and ecotoxicological properties. Leaching properties were determined with the European standard SFS-EN 12457-2 leaching-test. The toxicity of the leaching-test eluates was measured with plant-, bacteria- and enzyme-inhibition bioassays. Total organic carbon, formaldehyde and solvent concentrations in the solid wastes and in the leaching-test eluates were analysed. It seemed likely that leached formaldehyde caused very high acute toxicity in leaching-test eluates of the dry-booth residues. This hypothesis was based on the fact that the formaldehyde concentrations in the leaching-test eluates of the dry-booth residues were 62-75 times higher than the EC50 value reported in the literature for formaldehyde. The results of the water-curtain booth residues showed that the samples with the highest TOC and aromatic solvent concentrations were also the most toxic. The studied excess paint residues were complex organic mixtures and contained large amounts of compounds not identifiable from chemical data. Therefore, the evaluation of the hazard based solely on available chemical data is unlikely to be sufficient, as evidenced by our study. Our results show that harmful compounds remain in the solid waste and the toxicity results of their leaching-test eluates show that toxicity may leach from residues in contact with water at landfill sites. They also confirm the benefit of combining chemical and ecotoxicological assays in assessing the potential environmental hazard of complex organic mixtures found in wastes.

Mutagenicity of coal tar paints used in drinking water distribution systems.

The aim of this study was to evaluate the mutagenicity of coal tar paints used for coating drinking water tanks and pipes, as a preliminary screening for potential genotoxic hazards associated with leaching of mutagens into drinking water during water storage and distribution. To this end, the Salmonella/microsome assay was performed on different fractions of two paints. The fractions were obtained using different fractionation procedures (a sequential solvent extraction and an acid-base fractionation) for removing the presence of inhibitory components. Both fractionation procedures confirmed an extraordinarily high mutagenicity in both paints, with metabolic activation, much higher than the mutagenicity of the unfractionated paints. The acid-base fractionation was more time-consuming but gave higher mutagenicity recoveries and provided information as to the general nature of the genotoxic constituents, which were concentrated in the neutral fractions. On the other hand, the sequential solvent extraction by sonication was a shorter and simpler method and permitted to reveal the presence of direct-acting mutagens. It is concluded that the application of the Salmonella/microsome assay coupled with both fractionation methods may give complementary and confirmatory data on the genotoxic properties of these coal based paints, as a screening of the potential mutagenic/carcinogenic hazards derived from these materials used in drinking water distribution systems.

Ingestions considered nontoxic.

The authors have compiled a list of common household products and drugs that are frequently ingested by children and may be considered nontoxic unless taken deliberately or in large amounts. An understanding of the nontoxic ingestion should prevent overtreatment and decrease emergency room visits.

PIP: In 1980, the National Clearinghouse for Poison Control Centers (NCPCC) received 126,000 reports from Poison Control Centers, but the true incidence of ingestions was actually much higher. Only 1 in 50 ingestions may be reported, indicating that the majority of ingestions are innocuous. 70% of reported episodes occurred in children under 5 years of age. Nontoxic ingestions occur when a victim consumes a nonedible product that usually does not produce symptoms. No product is entirely safe and all can produce symptoms if a large enough concentration is consumed. Knowledge of nontoxic ingestions helps avoid overtreatment and its risks and serves as a warning of inadequate supervision or an improper and unsafe environment. The designation of nontoxic ingestion has 6 criteria: 1) absolute identification of the product 2) absolute assurance that only 1 product was ingested 3) no signal word (danger, poison, warning, caution) on the container 4) a good approximation of the amount ingested 5) assurance that the victim is free of symptoms and 6) the ability to call back at intervals to determine that no symptoms have developed. A good rule of thumb for the average drug that 5 times the therapeutic dose may be a toxic dose; opiate narcotics are the exception and require medical observation because of their narrow margin of safety. There are several points to consider in deciding wheter to decontaminate the gastrointestinal tract, including the toxicity of the ingested agent, the amount ingested, the elapsed time since ingestion, and the presence of symptoms. Emergency room referral is mandatory in case of exposure to highly toxic agents, of a dose sufficient to lead to anticipation of servere symptoms, of manifestations of toxic exposure such as alterations in vital signs already present, or of a history of intentional ingestion. A detailed discussion of frequently ingested nontoxic household items and related items that may be toxic includes writing and art materials, toiletries and laundry agents, deordorizers and disinfectants, tobacco and matches, medicinals, pesticides and insecticides, miscellaneous substances, petroleum distillate hydrocarbons, and plants. Hormonal contraceptives have been reported to produce almost no toxicity. A 1962-65 report from the NCPCC of 962 ingestions listed only 40 producing nausea nd vomiting even after consumption of 21 pills. An iron additive could make the ingestion toxic for iron.

Comparative carcinogenic and mutagenic activity of coal tar and petroleum asphalt paints used in potable water supply systems.

Coal tar and petroleum asphalt paints are among the products used as coatings for water pipes and storage tanks to retard corrosion. Formulations of these coatings were tested in the Ames mutagenesis and the mouse skin carcinogenesis bioassays. To test the mutagenicity of the paints, six doses ranging from 0.005 to 10 microliters per plate were assayed. In the mouse skin bioassay, doses of the coal tar paints ranging from 0.2 to 200 microliters were administered topically to 30 SENCAR mice per group. These initiating doses were followed by applications of 1.0 micrograms of 12-o-tetradecanoyl-phorbol-13-acetate (TPA) in 0.2 ml acetone topically, three times weekly for 20 weeks. Petroleum asphalt paints were tested in groups of 40 animals at 200 and 600 microliters doses. All coal tar paints showed mutagenic activity after metabolic activation with S-9, with the highest response being in strains TA 98 and TA 100. None of the petroleum asphalt paints gave mutagenic responses. Both types of coatings resulted in positive responses in the initiation/promotion study. The coal tar paints gave rise to 1000-1800 times the tumor response observed with petroleum asphalt products. One coal tar product was positive when tested as a complete carcinogen in the mouse at 2 microliters per application once weekly for 30 weeks, whereas the asphalt paint was negative at 100 times the dose. The biological responses to the products were greater than expected from their polycyclic aromatic hydrocarbon (PAH) content. These findings suggest that the hazard posed by these coatings may not be fully explained by their PAH contents.