Contribution to pollution by different types of vehicles based on age and number

This study assessed the smoke, hydrocarbon (HC), and carbon monoxide (CO) emissions from a range of age groups and car types. The results show a distinct trend of rising emissions with vehicle age, with older cars having the greatest emission levels. Older cars (20+ years) had emissions of CO (18.83 times higher), HC (5.81 times higher), and smoke (3.97 times higher) than newer cars (0–5 years), suggesting that older cars play a major role in air pollution. Similar to cars, motorbikes showed a significant increase in emissions. In the group of people aged 5 to 10, CO emissions increased from 0.63 times to 7.00 times, while HC emissions increased from 0.72 times to 6.20 times. Both trucks and buses showed similar trends: for vehicles older than 20 years, CO emissions peaked at 3.28 times and HC at 6.20 times, while for buses, CO emissions peaked at 1.55 times and smoke levels peaked at 5.50 times. The CO emissions of autorickshaws, which are often utilized in metropolitan areas, also increased significantly with age. For example, the CO emissions of autorickshaws increased from 0.97 times in the 5–10 year group to 13.85 times in cars over 20 years old. These results illustrate the negative effects that older cars have on the environment and the necessity of stricter emissions standards for fleets of aging cars.