Long-term air pollution exposure increases dementia risk: What new study has found – The Indian Express

Report on the Link Between Air Pollution and Dementia Risk in the Context of Sustainable Development Goals

1.0 Introduction

A comprehensive assessment by Cambridge University, published in The Lancet Planetary Health, establishes a statistically significant link between long-term exposure to common air pollutants and an increased risk of developing dementia. This report summarises the study’s findings, which are based on a systematic review of 51 studies involving over 29 million participants. The implications of this research are critically relevant to the achievement of several United Nations Sustainable Development Goals (SDGs), most notably SDG 3 (Good Health and Well-being) and SDG 11 (Sustainable Cities and Communities).

2.0 Key Findings on Air Pollutants and Dementia Risk

The study identified a positive association between dementia and three specific air pollutants, highlighting a direct challenge to SDG 3, Target 3.9, which aims to substantially reduce the number of deaths and illnesses from hazardous chemicals and air pollution.

1. Particulate Matter 2.5 (PM2.5): For every 10 micrograms per cubic metre (µg/m³) increase in long-term exposure to PM2.5, the relative risk of dementia increases by 17%. Primary sources include vehicle emissions and thermal power plants, activities directly related to urban infrastructure and energy production.
2. Nitrogen Dioxide (NO2): For every 10 µg/m³ increase in long-term exposure to NO2, the relative risk of dementia increases by 3%. This pollutant is primarily generated by the burning of fossil fuels in vehicles, power plants, and industrial processes.
3. Soot (Black Carbon): For each 1 µg/m³ increase in long-term exposure to soot, the risk of dementia increases by 13%. Soot originates from sources like vehicle exhaust and wood burning.

3.0 Health Implications and Alignment with SDG 3

The study’s findings underscore the environmental determinants of non-communicable diseases (NCDs), a core focus of SDG 3. Dementia is a progressive illness affecting memory and cognitive function, with global cases projected by the WHO to rise from 57 million in 2021 to 150 million by 2050. Air pollution acts as a significant risk factor through two primary mechanisms:

• Inflammation in the brain: Pollutants can trigger inflammatory responses that contribute to neurodegeneration.
• Oxidative stress: An imbalance caused by pollutants can lead to cellular damage in the brain.

By identifying air pollution as a modifiable risk factor for dementia, this research reinforces the urgency of Target 3.4 (reduce by one-third premature mortality from NCDs) and Target 3.9. The fact that 99% of the global population breathes air exceeding WHO guideline limits, with the highest exposures in low- and middle-income countries, presents a major obstacle to ensuring healthy lives for all.

4.0 Broader Implications for Sustainable Development

The report’s conclusions extend beyond public health, necessitating an integrated policy approach that aligns with multiple SDGs.

• SDG 11: Sustainable Cities and Communities: The study directly implicates urban and transport policies as crucial for dementia prevention. Achieving Target 11.6 (reduce the adverse per capita environmental impact of cities, including air quality) is now demonstrably linked to reducing the burden of neurological disease.
• SDG 7: Affordable and Clean Energy: The sources of the identified pollutants—thermal power plants and fossil fuel combustion—highlight the public health co-benefits of transitioning to cleaner energy sources, as outlined in Target 7.2 (increase substantially the share of renewable energy).
• SDG 13: Climate Action: Actions taken to reduce air pollution by curbing fossil fuel emissions will simultaneously contribute to climate change mitigation efforts, creating a synergistic effect that benefits both planetary and human health.

5.0 Conclusion: An Interdisciplinary Path Forward

The link between air pollution and dementia risk strengthens the case for policy coherence across sectors. Preventing dementia is not solely a healthcare responsibility but a collective goal requiring action in environmental regulation, urban planning, and energy policy. To advance the 2030 Agenda for Sustainable Development, an interdisciplinary approach is essential to mitigate air pollution, thereby protecting brain health, promoting well-being, and creating sustainable, healthy environments for all populations.

1. Which SDGs are addressed or connected to the issues highlighted in the article?

The article primarily addresses issues related to the following Sustainable Development Goals (SDGs):

• SDG 3: Good Health and Well-being

  This goal is central to the article, which focuses on the health impacts of air pollution. The entire study discussed is about the link between long-term exposure to air pollutants and an increased risk of developing dementia, a non-communicable disease that affects memory, thinking, and overall well-being. The article cites WHO data on the global prevalence of dementia and its expected rise, directly connecting environmental factors to public health outcomes.

• SDG 11: Sustainable Cities and Communities

  The article connects the problem of air pollution directly to urban environments. It mentions that pollutants like PM2.5 and NO2 are “predominantly produced by vehicle emissions and thermal power plants,” which are major components of city infrastructure. It provides specific pollution data from “Delhi’s ITO pollution AQI monitoring station.” Furthermore, the conclusion explicitly calls for policy changes in “urban planning, transport policy, and environmental regulation” to mitigate the risk, reinforcing the link to creating sustainable and healthy cities.

2. What specific targets under those SDGs can be identified based on the article’s content?

Based on the article’s content, the following specific targets can be identified:

1. Target 3.9: By 2030, substantially reduce the number of deaths and illnesses from hazardous chemicals and air, water and soil pollution and contamination.

   The article directly supports this target by establishing a “positive and statistically-significant association between three common air pollutants and dementia.” It quantifies how exposure to PM2.5, NO2, and Soot increases the risk of dementia, which is an illness resulting from air pollution. The study’s findings highlight the urgency of reducing air pollution to prevent such illnesses.

2. Target 3.4: By 2030, reduce by one-third premature mortality from non-communicable diseases through prevention and treatment and promote mental health and well-being.

   Dementia is a non-communicable disease that severely impacts mental health and well-being. The article focuses on prevention by identifying a key environmental risk factor (air pollution). The quote from Dr. Christiaan Bredell emphasizes an “interdisciplinary approach to dementia prevention,” which aligns with the preventative aspect of this target.

3. Target 11.6: By 2030, reduce the adverse per capita environmental impact of cities, including by paying special attention to air quality and municipal and other waste management.

   This target is directly relevant as the article uses a major city, Delhi, as an example of high pollution levels. It discusses pollutants generated by urban activities like vehicle emissions and industrial processes. The call to action involving “urban planning, transport policy, and environmental regulation” is a direct recommendation for reducing the adverse environmental impact of cities, with a specific focus on improving air quality.

3. Are there any indicators mentioned or implied in the article that can be used to measure progress towards the identified targets?

Yes, the article mentions and implies several indicators that can be used to measure progress:

• Concentration of specific air pollutants

  The article provides specific measurements for pollutants, which serve as direct indicators for Target 11.6 and as proxy indicators for the environmental health risks in Target 3.9. Examples include:

  • PM2.5 concentration: The article mentions “10 micrograms per cubic metre (µg/m³)” as a measure of exposure and gives a real-world example: “average PM2.5 levels at Delhi’s ITO pollution AQI monitoring station… was 77.”
  • NO2 concentration: It refers to “10 μg/m³ of long-term exposure to nitrogen dioxide” and provides a measurement from Delhi: “The average NO2 levels at the ITO station… was 83.”
  • Soot (Black Carbon) concentration: The risk is measured per “1 μg/m³ of long-term soot exposure.”

• Prevalence and incidence of dementia

  As an indicator for Target 3.4, the article provides data on the burden of the non-communicable disease. It states, “some 57 million people had dementia worldwide in 2021, with the number expected to increase to at least 150 million cases by 2050.” Tracking the actual number of cases over time against these projections would be a key indicator of the success of preventative measures.

• Percentage of the population breathing polluted air

  The article implies this indicator by citing WHO data that “99% of the global population breathes air that exceeds WHO guideline limits.” Reducing this percentage would be a clear measure of progress towards improving air quality and public health.

4. Create a table with three columns titled ‘SDGs, Targets and Indicators” to present the findings from analyzing the article. In this table, list the Sustainable Development Goals (SDGs), their corresponding targets, and the specific indicators identified in the article.

Source: indianexpress.com