MedicalResearch.com Interview with:
Dr Rebecca Ghosh, Research Associate
Small Area Health Statistics Unit (SAHSU)
MRC-PHE Centre for Environment and Health
Imperial College London
St Mary’s Campus, Norfolk Place, London
Medical Research: What is the background for this study? What are the main findings?
Dr. Ghosh: Since the 1950s a lot of evidence has accumulated that high levels of air pollution cause harmful effects on health. However there is limited evidence on the very long term (>25 years) effects of air pollution. Our study is one of the longest running to date looking at air pollution and mortality, following 368,000 people in England and Wales for 38 years. We estimated air pollution exposures throughout England & Wales for 1971, 1981, 1991 and 2001 using data from historic air pollution monitoring networks, the first time this has been done.
We found that air pollution exposure in 1971 was still associated with a small increased risk of death in 2002-9, over 30 years later, suggesting that harmful effects of air pollution are extremely long-lasting. However, risks from an individual’s past exposures waned over time and their more recent exposures gave the highest mortality risks.
Medical Research: What should clinicians and patients take away from your report?
Dr. Ghosh: We already knew that breathing in air pollution is harmful to health in the short-term, our studies provides new evidence about how long-lasting the effects may be. However, it’s important to put this into perspective. We found that the increased risk of mortality in recent years related to living in a highly polluted areas 1970s was 14% higher than if you lived in an area with low air pollution. Individual lifestyle factors can have much higher effects, for example being a smoker can increase your mortality risk by 200%.
Medical Research: What recommendations do you have for future research as a result of this study?
Dr. Ghosh: Our study found more recent exposures were a more important determinant of mortality risk than what you were exposed to a long time in the past, but we need to do more research on how air pollution affects health over a person’s entire lifetime. In particular, research is needed to estimate how many deaths were linked with historic vs. recent air pollution levels. This is not easy to do, because the way in which air pollution has been measured over time has changed.
Medical Research: Is there anything else you would like to add?
Dr. Ghosh: We think our study adds another reason to try to reduce air pollution as much as we can as our results indicate this could result in short and very long term health consequences. Our results are particularly relevant to countries such as China currently experiencing high levels of air pollution.
Dr Rebecca Ghosh (2016). Harmful Effects of Air Pollution Can Last Decades