Impacts of climate change on public health in India - Future research directions - Paper published in Environmental Health Perspectives

This paper published in the journal Environmental Health Perspectives reviews the current state of the science relevant to the 2009 Joint Indo–U.S. Workshop on Climate Change and Health that was held in Goa, India, and, then discusses the observed relationships between climate variability and human health specifically in relation to the Indian subcontinent, highlighting future research directions.

The paper briefly summarises relevant literature on the impacts of climate change in India and touches upon the opportunities and significant challenges associated with designing, initiating, and conducting research, as well as pursuing related public health programming to improve public health infrastructure in the face of climate change. The paper argues that such research is needed to pave the way for unique and pioneering solutions that can improve public health in the face of increasing climate variability.

The paper highlights the following impacts of climate change in India and identifies areas for research and intervention:

Poverty and baseline vulnerability
Many of the predicted effects of climate change are likely to become a reality in India with its increasing population and rate of urbanisation.Climate change poses an overwhelming stressor that will magnify existing health threats. The paper argues that future studies must work to more explicitly define the relationship between climate variability and emerging and reemerging infectious diseases such as dengue, yellow fever, cholera, and the chikungunya virus, as well as chronic diseases related to cardiovascular and respiratory illness, asthma, and diabetes.

These problems stand the risk of being exacerbated in the context of poverty and deprivation. Millions of people below the poverty line and those in rural areas represent high-risk populations who are exposed to health risks, including poor sanitation, pollution, malnutrition, and a constant shortage of clean drinking water. Future research needs to explore the linkages between these emerging and reemerging diseases, climate change and the socioeconomic and cultural contexts that might be creating favourable conditions for diseases to occur among populations and can be useful to devise prevention strategies to control the spread of these diseases in populations.

Waterborne infectious disease
The burden of waterborne disease in India is enormous. However, estimates vary widely because of a lack of reporting, poor surveillance, and minimal data infrastructure. Approximately 73% of the rural population in India does not have proper water disinfection, and 74% do not have sanitary toilets. Freshwater availability in India is also a concern. Available water is expected to decrease from 1,820 m3 per capita to < 1,000 m3 by 2025 in response to the combined effects of population growth and climate change.

Research in this area must be both temporally and spatially specific. Furthermore, it requires local monitoring of the appropriate climate and disease variables because underreporting impedes the development of effective prevention strategies. It is critical to build a data infrastructure and conduct such research in India so that region-specific models based on climate and health can be developed.

Heat stress and air pollution
Research linking temperature and health effects in India is sparse. Limited work has been conducted on the combined effects of weather, climate variability, and increased air pollution in India. Whether these health risks will be exacerbated as a result of climate change is yet to be determined, but cobenefit interventions aimed at reducing the health impacts associated with indoor air pollution, decreasing the release of green house gases from the burning of solid fuel, and preventing deforestation by introducing alternative, more efficient stoves and fuels will have serious implications for health and society.

Vector borne disease
Evidence suggests that rainfall variability plays an important role and that a long-term trend in increasing temperature during the 20th century is sufficient to significantly increase the abundance of vectors. Monthly parasite incidence can be positively correlated with temperature, precipitation, and humidity. The implications of this association as it relates to long-term climate change remain an important open question and needs further exploration. For example, the rapid spread of malaria in urban and rural areas in India has been correlated to climate related changes.

The need for adaptation
Although adaptation to climate impacts has attracted substantial attention recently, the effectiveness of specific strategies in relation to greater resilience of public health systems remains under investigated. Furthermore, adaptation strategies in response to climate variability and change must be designed on specific temporal and spatial scales relevant to India.

Potential adaptation strategies in India could focus on controlling infectious diseases by removing vector breeding sites, reducing vector–human contact via improved housing, and coordinating monitoring of mosquitoes, pathogens, and disease burden. Another potential focus area for adaptation could be improving sanitation and drinking water by supporting inexpensive and effective water treatment and increasing rainwater harvesting,safe storage, and gray-water reuse

Current surveillance and data sources
Successful work in this area will require the health community to partner closely with climate scientists and development professionals to move beyond the assessment of climate variability and disease outcomes to predictive models accounting for climate change to facilitate targeted adaptation.

The paper makes the following recommendations based on the Goa workshop and subsequent discussions, to advance research relevant to climate change and human health:

• Environmental monitoring and surveillance: Need to improve environmental monitoring and surveillance systems in low and middle income countries such as India
• Geospatial technology: Geographic information systems and spatial analysis must be further developed; they are very useful tools when conducting vulnerability assessments, assessing environmental exposures, prioritising research, and disseminating findings to decision makers and the public alike
• Human and technical capacity: For these new surveillance methods and analytical techniques to be effective, countries like India will need to enhance their human and technical capacity for risk communication. This could take the form of public education on climate change and associated health impacts to enhance awareness and to influence lifestyle, behavior, and individual choices to protect and improve health

The paper ends by arguing that innovative, multidisciplinary investigations using environmental epidemiologic methods to elucidate health risks posed by climate variability and subsequent climate change in regions such as India are possible. However, such work needs to have expanded partnerships among researchers, governments, and communities to develop a cobenefit strategy that addresses public health challenges and risks associated with climate change.

A copy of the paper can be accessed from this link