Psychological Impact of Vehicle Exhaust Exposure: Insights from an Animal Model

Abstract

Air pollution resulting from exhaust emissions of vehicles has risen in the recent years, reportedly causing major adverse effects on the heart, lungs and the brain. Though respiratory and cardiovascular effects of these emissions are well identified, psychological and neurobiological complications of prolonged exposure to vehicle emissions remain unknown. Pro-oxidants are considered as major constituents of vehicle emissions. This is important considering causal link between oxidative stress and behavioral and cognitive impairments. We hypothesized that prolonged exposure to pro-oxidants in vehicle emissions result in behavioral and cognitive deficits. We developed a simulated vehicle exhaust exposure model in rats. The model used a simulated mixture of vehicle exhaust that comprised of pro-oxidant constituents of exhaust, namely, carbon dioxide (13%), carbon monoxide (0.68%) and nitrogen dioxide (1000 ppm) in air. Rats were exposed either to a high (1:10 dilution) or low (~1:1000 dilution) physiologically relevant dose of simulated mixture in air for two weeks in separate experiments followed by a comprehensive behavioral and cognitive analysis. We observed that prolonged exposure to pro-oxidants in vehicle exhaust increased anxiety-and depression-like behavior as well as led to impaired memory in rats. This is important preclinical evidence, particularly relevant to human population exposed to high vehicular traffic.

Is there a link between air pollution and impaired memory? Evidence on 34,000 english citizens

“…The paper's findings are consistent with the hypothesis that polluted air is dangerous for the human brain. Our conclusions seem complementary to the result demonstrated in laboratory studies such asSalvi et al (2017) that rats' memories, for example, are impaired by air pollution. The potential strengths of the current study are its large sample, the national representativeness of the sample, and the use of instrumental-variable methods.…”

“…There is evidence of potential damage to the structure of the adult human brain, and of adverse effects, under controlled laboratory conditions, upon non-human animals (Calderon-Garciduenas et al 2008;Killin et al 2016). Salvi et al (2017) recently showed evidence of memory impairment in laboratory rats that were exposed to air pollution.…”

Ambient concentrations of NO2 and hospital admissions for schizophrenia

“…Exposure to NO 2 may increase the risk of schizophrenia admissions through increased neuroinflammation and oxidative stress,28 29 as supported by the following findings from animal studies: associations between diesel exhaust inhalation and neuroinflammation in brain regions,30 relationship between NO 2 inhalation and brain pathology, lower antioxidant defences and deregulation of apoptosis-related genes expression,31 links between diesel exhaust and microglial activation and upregulation of oxidative stress,28 and associations between vehicle emissions and anxiety-like behaviour, depression-like behaviour, neurobehavioural as well as cognitive deficits 24. Epidemiological research also indicated that traffic-related air pollution was associated with autism and decreased cognitive function 11 32 33.…”

“…First, since traffic is an important source of NO 2 , in order to explore whether the association was sensitive to the effects of other traffic-related pollutants, such as PM 10 and CO,24 two-pollutant and three-pollutant models were fitted. According to the observed shape of C–R (online supplementary figure S1), PM 10 and CO were included as non-linear terms in models, respectively.…”

Commuting on Public Transport: Health Risks and Responses

“…However, the impact of air pollution on psychological health is equally prominent. In an animal model, exposure to exhaust emissions increased anxiety-and depression-like behavior and led to impaired memory in rats [48]. Few studies reported psychological health impacts in Western countries [49,50]; however, psychological health impacts of being exposed to vehicular traffic-related pollutants have rarely been evident in the Asian region.…”