Results of a study by a team from Health Canada and Environment Canada suggest that the use of B5 and B20 biodiesel fuel blends (5 per cent and 20 per cent biodiesel, respectively) compared to diesel in heavy-duty trucks will result in very minimal changes in air quality and health benefits or costs across Canada, and says these are likely to diminish over time.
When used in heavy-duty trucks, biodiesel fuels generally decrease emissions of particulate matter (PM), carbon monoxide (CO), hydrocarbons and volatile organic compounds (VOC), and slightly increase or have no net impact on nitrogen oxides (NOx) emissions.
The study assessed the potential human health implications of the widespread use of biodiesel in Canada compared to those from ultra low sulphur diesel (ULSD) in 2006 and 2020. Computer models estimated changes in human health outcomes, based on the impacts of on-road mobile source emission scenarios on ambient concentrations of PM, ozone, CO, nitrogen dioxide and sulphur dioxide.
The use of biodiesel in heavy-duty diesel vehicles decreased exhaust emissions of most pollutants, with the exception of a slight increase in NOx emissions. In general, the proposed biodiesel scenarios were associated with very minimal changes in modelled air pollutant emissions and ambient air concentrations. These changes would likely be well below any possible verification by ambient monitoring.
Results for 2020 showed smaller health benefits or drawbacks under the different biodiesel use scenarios, resulting partly from the lower impact of biodiesel fuel use on truck emissions with the introduction of cleaner vehicles.
Overall, the researchers noted, the results of their study concurred with those from previous assessments of the impact of biodiesel use on ambient air concentrations for regions of the US and Canada. These assessments estimated that the use of biodiesel would likely lead to negligible or non-measurable impacts on air quality.