Air pollution raises risk of dementia, say Cambridge scientists – The Guardian

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

Executive Summary

A comprehensive systematic review has established a statistically significant link between exposure to specific air pollutants and an increased risk of developing dementia. The findings, derived from 51 studies involving over 29 million participants, have profound implications for public health strategies and the achievement of several United Nations Sustainable Development Goals (SDGs), particularly SDG 3 (Good Health and Well-being) and SDG 11 (Sustainable Cities and Communities).

Key Research Findings

The study, conducted by the University of Cambridge and published in The Lancet Planetary Health, provides robust evidence on the neurological risks of air pollution. The global dementia burden is currently estimated at 57 million people and is projected to rise to 150 million by 2050, making risk factor mitigation a global health priority.

• A positive and statistically significant association was confirmed between dementia and long-term exposure to three specific air pollutants.
• For every 10 micrograms per cubic metre (µg/m³) increase in PM2.5, an individual’s relative risk of dementia increases by 17%.
• For an equivalent increase in soot, the dementia risk rises by 13%.
• In 2023, levels of PM2.5 and soot approached or exceeded these risk-associated thresholds at various roadside locations in major UK cities, including London, Birmingham, and Glasgow.

Implicated Pollutants and Their Sources

The research identified three primary pollutants linked to increased dementia risk. The sources of these pollutants are directly related to industrial and urban activities that are targets for reform under the SDGs.

1. Particulate Matter (PM2.5): Originates from vehicle emissions, power plants, and the burning of wood in stoves and fireplaces.
2. Nitrogen Dioxide (NO₂): A byproduct of burning fossil fuels in vehicles and for power generation.
3. Soot (Black Carbon): Comes from sources including vehicle exhaust emissions and wood burning.

Implications for Sustainable Development Goals (SDGs)

The report’s conclusions underscore the interconnectedness of environmental health and human well-being, highlighting the urgent need for integrated policy action to meet the 2030 Agenda.

• SDG 3: Good Health and Well-being: The findings directly impact Target 3.4, which aims to reduce premature mortality from non-communicable diseases, and Target 3.9, focused on reducing deaths from air pollution. Mitigating air pollution is a critical public health intervention to protect brain health and reduce the immense burden of dementia on individuals, families, and healthcare systems.
• SDG 11: Sustainable Cities and Communities: The research provides a clear health-based rationale for advancing Target 11.6, which calls for reducing the adverse environmental impact of cities by improving air quality. The high pollution levels in urban centres represent a direct failure to create safe and healthy living environments.
• SDG 7 (Affordable and Clean Energy) & SDG 13 (Climate Action): The primary sources of the implicated pollutants are fossil fuel combustion. This reinforces the necessity of transitioning to clean energy sources (SDG 7) not only for climate mitigation (SDG 13) but as a crucial co-benefit for public health.
• SDG 10: Reduced Inequalities: The report acknowledges a research limitation, as most studies involved participants from high-income countries. This highlights a need for future research to include more participants from marginalised and diverse backgrounds to ensure that public health strategies address health inequalities effectively.

Expert Recommendations and Call for Coordinated Action

Experts stress that air pollution is a major modifiable risk factor for dementia that requires systemic, not just individual, solutions. This aligns with the SDG principle of integrated and cross-sectoral policy.

• A bold, cross-government approach is required to tackle the drivers of dementia risk, uniting departments of health, environment, and energy.
• Government leadership is considered vital to implement large-scale changes to tackle the “invisible threat” of air pollution.
• Addressing air pollution is framed as an investment that can deliver long-term health, social, climate, and economic benefits, contributing to a more sustainable and equitable future.

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

• SDG 3: Good Health and Well-being

  The article’s central theme is the direct impact of air pollution on human health. It explicitly links exposure to pollutants like PM2.5 and nitrogen dioxide to an increased risk of dementia, a non-communicable disease. The article states that dementia affects “about 57 million people worldwide” and that tackling air pollution can “reduce the immense burden on patients, families, and caregivers, while easing pressure on overstretched healthcare systems.”

• SDG 11: Sustainable Cities and Communities

  The article identifies the sources of pollution as being concentrated in urban areas. It mentions “vehicle emissions, power plants and woodburning stoves” and notes that harmful levels of pollutants “approached or exceeded” recommended levels in “roadside locations in central London, Birmingham and Glasgow.” This directly relates to the environmental quality and sustainability of cities.

• SDG 7: Affordable and Clean Energy

  The article points to the “burning of fossil fuels” and “power plants” as primary sources of the harmful pollutants. This connects the health crisis to the methods of energy production, implicitly advocating for a transition to cleaner energy sources to mitigate air pollution.

• SDG 13: Climate Action

  A direct connection is made when the article states that “Tackling air pollution can deliver long-term health, social, climate and economic benefits.” It recognizes that the sources of air pollution, such as “the burning of fossil fuels” and “vehicle exhaust emissions,” are also the primary drivers of climate change, highlighting the co-benefits of addressing these issues simultaneously.

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

1. SDG 3: Good Health and Well-being

   • 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.
     
     Explanation: The article focuses on dementia, a non-communicable disease, and discusses its prevention by tackling a major risk factor: air pollution. The call to action aims to reduce the incidence of dementia, which aligns with preventing premature illness and promoting well-being.
   • Target 3.9: By 2030, substantially reduce the number of deaths and illnesses from hazardous chemicals and air, water and soil pollution and contamination.
     
     Explanation: This target is directly addressed. The article is entirely about illnesses (dementia, respiratory diseases, heart problems) caused by air pollution from specific sources like PM2.5, nitrogen dioxide, and soot.

2. SDG 11: Sustainable Cities and Communities

   • Target 11.6: By 2030, reduce the adverse per capita environmental impact of cities, including by paying special attention to air quality.
     
     Explanation: The article’s focus on air pollution levels in major cities like London, Birmingham, and Glasgow directly relates to this target. The call for government leadership to “tackle this invisible threat” is a call to improve urban air quality.

3. SDG 7: Affordable and Clean Energy

   • Target 7.2: By 2030, increase substantially the share of renewable energy in the global energy mix.
     
     Explanation: While not explicitly mentioned, this target is strongly implied. Since the article identifies “power plants” and the “burning of fossil fuels” as key pollution sources, a logical solution is to shift away from these energy sources towards cleaner alternatives, which is the goal of Target 7.2.

4. SDG 13: Climate Action

   • Target 13.2: Integrate climate change measures into national policies, strategies and planning.
     
     Explanation: The article calls for a “bold, cross-government approach to health prevention – one that brings together departments beyond health, including Defra [Department for Environment, Food & Rural Affairs], to take coordinated action on the drivers of dementia risk.” This aligns with integrating climate and environmental measures (tackling pollution from fossil fuels) into national health policy.

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

1. For SDG 3 (Good Health and Well-being)

   • Indicator 3.9.1: Mortality rate attributed to household and ambient air pollution.
     
     Explanation: The article directly supports this by linking air pollution to an increased risk of dementia and other fatal conditions. Progress could be measured by tracking mortality and morbidity rates for these diseases in relation to air pollution levels.
   • Implied Indicators:
     • The number of people affected by dementia (currently “57 million people worldwide,” projected to be “150m cases by 2050”).
     • The relative risk increase of dementia per unit of pollutant (“for every 10 micrograms per cubic metre of PM2.5, an individual’s relative risk of dementia would increase by 17%”).

2. For SDG 11 (Sustainable Cities and Communities)

   • Indicator 11.6.2: Annual mean levels of fine particulate matter (e.g. PM2.5 and PM10) in cities (population weighted).
     
     Explanation: This indicator is explicitly mentioned in the article. It names “PM2.5” as a key pollutant and discusses its concentration levels (“10 micrograms per cubic metre”) and its presence in major cities. Measuring the levels of PM2.5, nitrogen dioxide, and soot in urban areas would be a direct way to track progress.

4. Table of SDGs, Targets, and Indicators

Source: theguardian.com