Resources Himalaya Foundation and Environmental Graduates in Himalaya successfully organized 115th series of Pralad Yonzon Conservation Forum (PYCF) with Dr. Narayan Babu Dhital, Assistant Professor of Environmental Science at Patan Multiple Campus, Tribhuvan University. He gave a talk on the topic “Inter modal comparison of air pollutant emissions and commuters’ exposure between public and private modes of passenger transportation”.
The talk started with Dr. Dhital briefing about the emission factor and passenger load factor from a case study conducted in Taiwan and stated that load effect on the fuel consumption is subtle at the speed bins below 20kmh-1. The case study results showed that during the pandemic scenario, Taiwan bus companies did not modify the bus frequency; however there was a significant impact in the bus occupancy which dropped during the pandemic. Dr. Dhital highlighted the comparison of emissions between different modes of transportation. Despite the very small engine of a motorcycle, it emits a significant amount of Carbon monoxide (CO) and Total Hydrocarbon (THC). For Nitric Oxide (NO), buses have the highest emission and the results are the same for Carbon dioxide (CO2) and fuel consumption rate (FC). For per Passenger Kilometer Travel (PKT), motorcycles emit the highest CO and THC, however, cars have the highest CO2 emitting factor. Further, he elaborated the result from exposure assessment which was carried out by comparing the heartbeat rate and ventilation rate of commuters in different modes of transportation. The result showed commuters with bicycles are highly exposed to air pollution. The overall result on comparison between different modes of transportation showed that bicycles have no emission but high exposure and inhalation dose; motorcycles have very high per capita emission; and commuters have high exposure with low to moderate inhalation dose. For public buses, the per capita emission was either high or low depending on the passenger load but the exposure and inhalation dose was low. He concluded the talk by sharing the key messages that if the roadside pollution is high, it is harmful to use active transportation like cycling. Lastly, he highlighted that for future research in Nepal, if we evaluate the environmental performance and social acceptability of the public transport system, it could be very beneficial for public bus companies as well as transport control authorities. The presentation was followed by an interaction session between the guest speaker and the participants and ended with a vote of thanks and closing remarks from Dr. Dinesh Raj Bhuju, Chairperson of Resources Himalaya Foundation.