Health Effects of Subchronic Exposure to Diesel–Water Emulsion Emission

Abstract

The U.S. Environmental Protection Agency (EPA) National Ambient Air Quality Standards for ozone and particulate matter are requiring urban nonattainment areas to implement pollution-reduction strategies for anthropogenic source emissions. A type of fuel shown to decrease combustion emissions components versus traditional diesel fuels is the diesel-water emulsion. The Lubrizol Corporation in conjunction with Lovelace Respiratory Research Institute and several subcontracting laboratories recently conducted a rodent health assessment of inhaled combustion emissions of PuriNO(x) diesel fuel emulsion. Combustion emissions from either of two 2001 model Cummins 5.9-L ISB engines were diluted with charcoal-filtered air to exposure concentrations of 100, 200, and 400 microg total particulate matter/m(3). The engines were operated on a continuously repeating, heavy-duty certification cycle (U.S. Code of Federal Regulations, Title 40, Chapter I) using Rotella-T 15W-40 engine oil. Nitrogen oxide and particulate matter were reduced when engines were operated on PuriNO(x) versus California Air Resources Board diesel fuel under these conditions. Male and female F344 rats were housed in Hazleton H2000 exposure chambers and exposed to exhaust atmospheres 6 h/day, 5 days/wk for the first 11 wk and 7 days/wk threafter. Exposures ranged from 58 to 70 days, depending on the treatment group. Indicators of general toxicity (body weight, organ weight, clinical pathology, and histopathology), neurotoxicity (glial fibrillary acidic protein assay), genotoxicity (Ames assay, micronucleus, sister chromatid exchange), and reproduction and development were measured. Overall, effects observed were mild. Emulsion combustion emissions were not associated with neurotoxicity, reproductive/developmental toxicity, or in vivo genotoxicity. Small decreases in serum cholesterol and small increases in platelet values in some groups of exposed animals were observed. Particulate matter accumulation within alveolar macrophages was evident in all exposure groups. These findings are consistent with normal physiological responses to particle inhalation. Other statistically significant effects were present in some measured parameters of other exposed groups but were not clearly attributed to emissions exposure. Positive mutagenic responses in several strains of Salmonella typhimurium were observed subsequent to treatment with emulsion emissions subfractions. Based on the cholesterol and platelet results, it can be concluded that the 100 microg/m(3) exposure level was the no-observed-effect level. In general, biological findings in diesel emulsion emission-exposed animals and bacteria were consistent with exposure to petroleum diesel exhaust in the F344 rat and Ames assays.

Health effects of subchronic exposure to diesel-water-methanol emulsion emission

“…However, the results of this, the third of three Tier II studies conducted at this institute on a novel alternative diesel fuel, were consistent with the mild biological responses observed after exposure to reasonable concentrations of biodiesel emissions (Finch et al, 2002) and another study of DEME (a Lubrizol emulsion fuel consisting of a dieselÁ/water blend, Reed et al, 2005). This body of evidence and that of other PDE exposure studies suggests that the risks of DEME are no greater than that of PDE and other alternative diesel fuels (Reed et al, 2004).…”

Bioremediation of diesel from a rocky shoreline in an arid tropical climate

“…Despite the strong culture of compliance of Australian resource companies to the standards governing the safe handling of hazardous and dangerous goods, loss of containment occurs on mining and resource construction operations (Guerin, 2014), in some cases with potentially significant impacts on aquatic and marine ecosystems, or even human health (Colombo et al, 2005;Hewstone, 1994;Ismail and Karim, 2013;Reed et al, 2005;Smith, 1995;Vazquez-Duhalt, 1989). Habitat loss and its effects on biodiversity are a growing global concern and is a major cause of the decline of coastal species.…”