Sick of waiting in traffic jams? You should be. A lot of us may not have given it a thought and therefore may not see that it’s actually harmful. Traffic jams are part of Nigerian life and are rife in Lagos and other cities. They consume a lot of time and manhours.
Pollution inside cars in traffic jams and at traffic lights is far higher than from cars that are moving. Now, a new research published in the Journal of Environmental Science offers a solution. Keep car windows shut.
Although, Nigeria adopted the “odd and even number” mechanism to control the volume of vehicles on the roads, it was discarded in the long run as it didn’t curb traffic jams in cities.
The World Health Organization (WHO) defines outdoor air pollution as a “major environmental risk to health,” linking it to 3.7 million premature deaths worldwide in 2012.
Air pollution contributes to lung cancer, asthma and other respiratory diseases and it has been associated with heart disease and stroke all of which can be fatal.
Other studies have also shown that people who are exposed to matter in air pollution from traffic for a prolonged time are at an increased risk of developing atherosclerosis.
This isn’t the first time that road traffic has been linked to heart disease. A previous study conducted in Denmark in 2012 indicated that traffic noise is significantly associated with risk of heart attack.
In 2013, WHO rated air pollution in cities as carcinogenic to humans as smoking was in February 1985.
In the United States, exposure to particulate matter in the air is the eighth leading cause of death each year. In London,United Kingdom, deaths related to air pollution are estimated to be 10 times higher than fatalities caused by road traffic accidents.
Research led by Dr. Prashant Kumar at the University of Surrey, United Kingdom, has shown that 25 percent of exposure to harmful particles when driving occurs in two percent of the journey time drivers spend at intersections with traffic lights.
At intersections, vehicles slow down, stop, rev up to move when lights turn green and they are closer together. In addition, in Lagos, because of bumps and bad roads, they are havens of accidents especially from reckless driving and these accidents cause traffic jams.
Due to traffic jams, levels of peak particle concentration at a signalized intersection are 29 times higher than those in free-flowing traffic. In addition, cars move slowly, so that drivers are exposed to pollution longer. This pollution lingers and accumulates.
Consequently, cars in traffic jams or at red lights emit up to 40 percent more pollution than those that are moving.
In a new study, Dr. Kumar and his team have been looking for a solution.
The scientists took measurements of particulate matter in a moving car under five different ventilation settings. The car traveled six (6) kilometers and passed through ten(10) different traffic lights.
They took measurements at 3-way and 4-way intersections managed by traffic lights.
The researchers wanted to see how different ventilation settings would affect particulate matter inside cars. They also looked at levels of pollution inside the car and compared with those experienced by pedestrians at the same traffic lights.
Results showed that the ventilation system of the car was efficient at removing coarse particles from the air, but as the concentration of coarse particles fell, the number of fine particles increased. The highest levels of pollution within the car tended to occur when the windows were shut at the traffic lights and the fan was on.
Pedestrians at intersections were also exposed to additional pollution, but the level of particulate matter to which motorists were exposed was up to seven times that experienced by pedestrians.
To reduce the amount of pollution exposure while waiting in traffic jams and at traffic lights, the researchers suggest that, weather permitting, motorists should shut car windows and switch off the fan.
This, they say, can reduce the chance of inhaling hazardous air by 76 percent.
They also recommend adjusting the fan so that the air circulates internally. Re-circulating the air prevents pollution from entering the car.
Where possible and weather conditions permitting, among the best ways to limit your exposure to pollution is by keeping windows shut, fans turned off and increasing the distance between you and the car ahead while in traffic jams or at traffic lights.
If the fan or heater needs to be on, the best setting would be to have the air re-circulating within the car without drawing in air from outside. Of course, improving the efficiency of filtering systems of vehicles in future could further curtail on-road exposure in such situations, said Dr. Prashant Kumar.
In 2015, Dr. Kumar and his team called on drivers to be aware of the hazards of pollution at intersections and suggested that keeping a distance from the car ahead could help reduce the risk.
The researchers urged pedestrians to find walking routes without signalized traffic intersections. They also noted that local transport authorities could help by synchronizing traffic signals as this can reduce waiting time.
Alternative traffic management systems such as flyovers could also help to alleviate the problem, they concluded.
