Acute effects of diesel emission from the urea selective catalytic reduction engine system on male rats

Abstract

Short-term inhalation experiments were performed using Fischer 344 rats exposed to emission from the urea selective catalytic reduction (SCR) diesel engine system to identify health effects and compare them to those of the conventional diesel engine system. Rats were exposed to high-, middle-, or low-concentration emission (dilution ratio 1:29, 1:290, or 1:580) or clean air (control) for 1, 3, or 7 days (6 h/day), under driving conditions at a speed of 1320 rpm and a torque of 840 Nm. For the high-concentration group, the major components of the urea SCR emission were 0.04 mg/m(3) particulate matter (PM) and 0.78 ppm nitrogen dioxide (NO(2)); those of the conventional emission were 0.95 mg/m(3) PM and 0.31 ppm NO(2). The authors evaluated the respiratory effects of each emission on rats. Lymphocytes for 3-day exposure of both emissions significantly increased in bronchoalveolar lavage fluid, but there were slight differences. With an increase in potential antioxidant (PAO), 8-hydroxy-2'-deoxyguanosine for the urea SCR emission was significantly decreased, but that of the conventional emission was highest among all groups and did not show a response to PAO. In lungs, heme oxygenase (HO)-1 and tumor necrosis factor (TNF)-alpha mRNA expressions for the urea SCR emission showed a tendency to increase compared to those of the conventional emission. Thus, gene analysis results suggested that NO(2) from the urea SCR emission affected the expressions of mRNAs in lungs. However, as a whole, the results suggested that the health effects of the urea SCR emission might be less than the conventional emission on rats.

A rapid assessment of the impact of hazard reduction burning around Sydney, May 2016

“…Urea selective catalytic reduction-treated diesel engine emissions (0.78 ppm NO 2 and dilutions) were generally less toxic to rat lungs than conventional diesel engine emissions (0.31 ppm NO 2 and dilutions), for various endpoints over durations of 1, 3 or 7 days. However, there were differences in the nature of the oxidative stress produced with either increases in 8-hydroxy-2-deoxyguanosine with conventional diesel engine emissions, or increases in haemoxygenase-1 mRNA expression with urea selective catalytic reductiontreated diesel engine emissions (Tsukue et al, 2010). The latter suggests oxidative stress related to NO 2 , but is not conclusive, given the mixture of constituents present.…”

Childhood Obesity and Environmental Chemicals

“…Adult male (females not tested) mice exposed to the cigarette smoke and diesel exhaust constituent benzo[ a ]pyrene had increased body weights and weight gain compared with unexposed mice 140. In another study, the longer that adult male rats were exposed to diesel exhaust, the greater the increase in their body weights 141. These effects have not been reproduced in cell culture, where differentiation of 3T3‐L1 preadipocytes, as well as their lipid accumulation, was decreased dose‐dependently up to the equivalent exposure to 1 pack of cigarettes 142…”

Murine precision-cut lung slices exhibit acute responses following exposure to gasoline direct injection engine emissions

“…Expressions of both CYP genes were elevated for mice exposed to diesel engine particulate matter compared to the control group. Upregulated Cyp1a1 mRNA expression was also found in an inhalation study of Fischer 344 rats exposed to diluted diesel engine exhaust compared to the filtered air control exposure group (Tsukue et al, 2010).…”