Navigating pollution: The impact of transportation modes on air and noise quality in Chattogram City, Bangladesh

Introduction

In-vehicle air and noise pollution pose a significant environmental challenge, particularly affecting daily commuters. This study evaluates real-time exposure to traffic-related air pollutants across different transport modes in Chattogram City, considering environmental parameters and noise levels to understand the in-vehicle environment.

Methods

A total of eight traffic routes and eight transportation modes-three with open environments (rickshaw, motorcycle, and boat) and five with confined environments (train, car, CNG, minibus, and bus) were studied both during day and evening hours. Six air pollutants (PM_2.5, PM₁₀, CO, CO₂, TVOC, and HCHO) and two environmental parameters (temperature and humidity) inside the vehicles alongside noise levels were measured.

Results

The findings revealed that air pollution was more severe in the evening, with open-environment vehicles exhibiting higher particulate matter levels compared to confined ones. The mean concentrations of PM_2.5 and PM₁₀ were found to exceed allowable limits in several modes, particularly the maximum in rickshaws and minibuses. The CO levels surpassed the Bangladesh standard limit across all modes, while CO₂ remained within an acceptable range but varied significantly based on transport modes. In contrast, TVOC levels were erratic, often exceeding permissible limits, whereas HCHO levels were within acceptable limits. Noise levels also exceeded allowable limits in all modes except waterways. Daytime humidity was high, while the temperature remained normal. The study reveals a significant correlation between particulate matter, gaseous pollutants, and climate factors. Major pollution sources were supposed to be due to pollution from construction sites, vehicle emissions, and industrial activities.

Conclusions

These findings underscore the urgent need for effective vehicular pollution management strategies in Chattogram City to mitigate health risks associated with air and noise pollution.