‘South Asia’s canal projects spread malaria’, says report
[NEW DELHI] Independent India should learn lessons from the deadly malaria epidemics that swept many parts of the country in the last century, attributable to indiscriminate canal building and related projects by the then rulers, a new study suggests.
The study by Elizabeth Whitcombe, visiting senior research scholar at the earth system science interdisciplinary centre, University of Maryland, US, in the May issue of Philosophical Transactions of the Royal Society, mapped meteorological, irrigation and medical reports during British rule in India.
Whitcombe analysed observations on geological and weather-related events, published by Geological Survey of India in its annual reports since 1870s and tallied them with records maintained by district medical officers, sanitary commissioners and registrars of births and deaths.
She found that a third of the deaths at that time were caused by “malarious” fevers. She also found that the incidence (new cases reported in a population) varied according to different regions in the Indo-Gangetic plain.
She concluded that "variations in the transmission, incidence and prevalence of malaria were closely tied to the different deltaic environments of the Bengal and Indus basins and to the short-sightedness of many irrigation and related engineering schemes."
Whitcombe told SciDev.Net that her paper shows how "the formation of IG (Indo Gangetic) deltas, monsoon and malarial transmission can be each analysed in terms of dynamic equilibrium over historical time from these incomparable British archives.
''This data and this form of analysis should be used to improve modern modelling of environmental factors controlling vector borne disease," she said.
Himanshu Thakkar, coordinator of the South Asia Network on Dams, Rivers and People, told SciDev.Net that the link between river basins and disease was known, but not studied in depth by “irrigation planners, engineers or environmental regulators.”
Thakkar said planners, even today, do not seem to have learnt any lessons from the past.
"The basic issue is firstly, provision of adequate drainage whenever additional water is added from outside a region. Secondly, to also assess the health-related implications and prepare management plans and to ensure that these get implemented before a project is implemented."
Ashvin Kumar Gosain, professor at the department of civil engineering, Indian Institute of Technology, Delhi, however, disagreed that scientists were ignoring the link between irrigation and disease. "Studies are being done even now and the linkage between river flows and disease is being studied once again in the context of climate change."