If you are searching for sarcasm in the following sentences, you will be disappointed. What you will find is sincere appreciation for two landmark scientific studies. In an extreme example of social asymmetry, while privileged individuals can debate whether or not to drink purified bottled water, over one billion others on this planet do not have access to clean drinking water.
I do not need to introduce cholera and other waterborne diseases to anyone from South Asia. These diseases infect hundreds of thousands (and possibly millions) in India and neighboring Bangladesh alone.
We have made strides in eradicating these diseases. In 1854, the British physician John Snow successfully traced the source of a cholera outbreak to a region of London in what is generally considered the first ever epidemiological study. Years later, one of the founding figures of microbiology, Robert Koch isolated and characterized the bacterium that causes cholera. Koch was also able to isolate cholera from contaminated pond water used by a community in India that was in the throes of a lethal epidermic. Koch published these results in the British Medical Journal in 1884 and won a Nobel Prize for other pioneering work on tuberculosis.
Now, a bit of background on the two research papers that I’d like to discuss today. Rita Colwell, a former director of the US National Science Foundation, is a renowned scientist who works on infectious diseases including cholera. In the 70s and 80s, her lab discovered that disease-causing cholera microbes clung to small organisms such as crustaceans in contaminated water. For reference, let me remind you that larger crustaceans that you are familiar with include crabs, shrimps, and lobsters.
Because of arsenic contaminated tube-well water, village populations in West Bengal, India and Bangladesh often drink surface water collected from rivers and ponds that contain small crustaceans. Boiling the water kills the disease-causing germs. On a personal note, I grew up drinking a lot of boiled water, but this approach isn’t feasible for poor people because of associated energy costs.
In a landmark scientific article published in the prestigious journal Proceedings of the National Academy of Sciences in 2003, Colwell and others tested a simple hypothesis in the field. Villagers in India and Bangladesh often use sari-cloth to filter water before drinking. Colwell asked a tantalizing question: if cotton sari-cloth can filter out crustaceans, can also it reduce the concentration of cholera microbes below a disease-causing threshold? Using the scientific method, she and other scientists followed villagers in 65 villages in Bangladesh for three years, and found that the low-tech process of filtering water through a cotton sari folded four-times resulted in almost 50% reduction in the incidence of cholera!
Colwell didn’t stop there. Researchers kept collecting data for years. Now, in new research published this month in the new journal mBio, Colwell and colleagues show that 31% of the villagers still use sari filtration. Therefore, not only is this process effective, it is also sustainable. This point is worth bearing in mind for any application to truly have real-world implications.
You may wonder why I mention these two studies today. Call me hopelessly naive, but I sincerely believe that the role of a scientist – especially one hailing from a developing country such as India – is to participate in building a better society through honesty, ingenuity, and dedication. To give you a sense of how I felt reading the two papers authored by Colwell, let me provide an imprecise cinematic analogy. In Asutosh Gowarikar’s Swades, Mohan Bhargava, the NASA scientist (played by Shahrukh Khan) provided an outlandish solution to the problem of lack of electricity in a village in India. The resolution in the film was exceedingly implausible, but the message resonated with me. I fervently believe that scientists and engineers have the wherewithal to come up with ingenious low-cost solutions for problems facing people in South Asia. There are many other examples, but these two papers underscore my belief in science as the only “candle in the dark”.
© Text, 2010-2012, Anirban