Air pollution, namely particulate matter 2.5 (PM2.5), is a global health concern with severe consequences for human health and the environment. 60% of countries worldwide have established air quality standards for at least one parameter to mitigate its impact, but the effectiveness of these standards vary significantly.
The PM2.5 standards established by different regulatory entities highlights significant differences in their approaches and results. The United States Environmental Protection Agency (USEPA), along with the World Health Organization (WHO), the European Union (EU), and Canada, have implemented rigorous PM2.5 standards with the aim of safeguarding public health and environmental well-being. In stark contrast, Bangladesh's Department of Environment (DoE) has encountered challenges in establishing effective standards, resulting in persistent air quality issues.
The DoE's air quality initiatives commenced with the Air Quality Management Project (AQMP) in the early 2000s, funded by the World Bank. During this project, the DoE installed several Continuous Air Quality Monitoring Stations (CAMS) in cities like Dhaka and Chittagong.
While initial progress was notable, structural inefficiencies within the DoE led to the departure of many skilled professionals involved in AQMP activities. Subsequently, the DoE initiated a larger endeavour named "The Clean Air and Sustainable Environment (CASE)" project, with execution handed over to a foreign development agency. Regrettably, the CASE project concluded without significant progress toward enhancing Bangladesh's air quality management framework.
Now, with potential funding from the World Bank on the horizon, the question arises: Should these resources be directed towards ensuring clean air for the next generation? Despite previous efforts, tangible outcomes such as health-based guidelines, advanced monitoring infrastructure, and effective dissemination of information to the public remain elusive. The allocation of resources for such endeavours could significantly benefit the populace, yet current indicators suggest a lack of a coherent management or mitigation strategy in Bangladesh's foreseeable future.
The USEPA has demonstrated a successful chronology of PM2.5 standards, gradually tightening regulations to protect public health. From 1997 to 2024, USEPA has consistently lowered the annual PM2.5 standard from 15 ug/m3 to 9 ug/m3, reflecting a commitment to evidence-based policymaking and continuous improvement in air quality management. This is truly a success story by the US government for its commitment to the people and their health.
Furthermore, Canada has emerged as a global leader in setting stringent PM2.5 standards, surpassing even the USEPA. With a 24-hour standard of 27 ug/m3 and an annual standard of 8.8 ug/m3, Canada's regulations prioritize the health and well-being of its citizens. Canada sets a precedent for proactive air quality management by implementing science-based standards that exceed international benchmarks. Similarly EU has a longstanding success story maintaining urban air quality in the entire region.
In comparison, DoE Bangladesh has faced challenges in setting rational PM2.5 standards. Despite efforts to emulate USEPA standards, such as adopting a 15 ug/m3 standard in 2005, Bangladesh has struggled to achieve meaningful progress. The recent standard of 35 ug/m3 set in 2022 raises questions about the rationale behind such decisions and the adequacy of measures to address air pollution effectively. The lack of a coherent strategy tailored to Bangladesh's unique context has hindered the country's ability to improve air quality and protect public health.
The divergence in PM2.5 standards among regulatory bodies underscores the importance of context-specific approaches and evidence-based policymaking. While emulating standards from other countries may seem appealing, it is essential to consider local factors such as geography, climate, and socio-economic conditions. A one-size-fits-all approach is unlikely to yield optimal results and may exacerbate existing challenges.
The WHO adheres to the principles of the GRADE approach for transparency and consistency. We can take notes from the WHO guidelines for formulating protection standards. It follows a systematic and thorough process in formulating air quality guidelines, which involves several key steps:
- Defining the scope of the guidelines and formulating key questions.
- Conducting a comprehensive review of relevant scientific evidence.
- Assessing the certainty level of the evidence obtained.
- Establishing air quality guideline levels based on evidence and assessments.
- Developing additional guidance to support guideline implementation.
The process of updating air quality guidelines is comprehensive and time-consuming, typically involving extensive consultations and meetings. This encompasses defining the scope, conducting systematic reviews, finalizing guideline levels, engaging in external consultations, and addressing feedback.
The WHO has been at the forefront of proposing stringent annual air quality guidelines for PM2.5, setting the bar at 5 ug/m3. As a pioneering health regulatory organization, WHO consistently prioritizes the health and safety of citizens globally.
To assist highly polluted cities or regions in meeting air quality standards, WHO suggests four interim levels: 35, 25, 15, and 10 ug/m3 for interim targets 1 through 4, respectively. These interim targets provide crucial milestones for regions to achieve their air quality objectives, including for Dhaka.
In order to ensure accurate reporting of air quality information and avoid misleading the public, it is imperative to revise the breakpoints used for estimating the air quality index (AQI). The Department of Environment can learn from the WHO and USEPA’s approach and consider implementing similar strategies to improve air quality management practices.
Moving forward, the DoE innBangladesh must prioritize the development of a comprehensive air quality management strategy tailored to its unique challenges. This strategy should incorporate scientific research, stakeholder engagement, and robust enforcement mechanisms to ensure effective implementation. Learning from the successes of countries like Canada, USEPA, and EU, Bangladesh can chart a path towards cleaner air and healthier communities for the coming generations.
Dr Md Firoz Khan is an Associate Professor and Group Leader (aerosol lab) in Environmental Science and Management at North South University (NSU) and a former visiting Professor at China University of Mining and Technology (CUMT), and a former Assistant Professor at the University of Malaya (UM) in Malaysia. Recipient of Dr. MA Wazed Miah International Gold Medal-2022 in the “Scientist” category. Email: [email protected]. Diya Mahmood, a student in environmental science and management at North South University (NSU).
