Arsenic Filters, Never Used

In 2002 a graduate student at MIT developed the Kanchan arsenic filter. Using simple and readily available materials these filters can remove arsenic from highly contaminated water, potentially providing clean water to hundreds of thousands of underserved people worldwide. Arsenic is a water contaminant naturally occurring in some groundwater that can cause cancers and organ failure. Unlike biotic contaminants, it cannot be removed by boiling or chlorination, making arsenic contamination traditionally difficult to treat. However, using just a bucket, rusty nails, and bricks the Kanchan filter provides clean, arsenic-free water. Clearly, this technology has the potential to improve many lives; it's cheap and easily maintained and it solves a costly and widespread problem.

But is it actually working? In order to actually be improving lives these filters need to be consistently used in the vulnerable populations. Otherwise, they risk causing more harm than good, by delaying a more permanent solution without actually providing clean water. The development of this technology must be coupled with effective implementation in order to actually fulfill its intended purpose.

In Bagaces canton, Guanacaste, Costa Rica arsenic contamination is a major health threat and has been the focus of several interventions in recent years. After initial studies found that groundwater contained unsafe levels of arsenic, a total of 974 Kanchan filters were distributed to households as a temporary measure. For the ministry of health, this was a successful intervention. If they were all used and used properly, these filters could have prevented additional months or years of arsenic exposure.

However, for many of the people in Bagaces, the filters were useless buckets of old nails that weren't worth using. After interviewing residents of Bagaces, we learned that an overwhelming majority of people did not use their filters, even when they thought the water was unsafe to drink. A representative of Voz del Pueblo, a local community activist group, described the filters as universally distrusted and disused, even by ministry of health officials for their own drinking water. Indeed, this problem is not unique to our area of study; household filters in Bangladesh were nearly equally unused, despite even higher arsenic levels that were well known in the community (Milton, et al. 2007). Despite the wide distribution of these filters, they fall far short of their potential because of poor communication and education.

As a hopeful future scientist and engineer, I think it is essential to see technology from this perspective. Too often we view a product as the end goal, and as a solution to the problem. In this case, a brief google search of "MIT arsenic filter" yields plenty of articles congratulating the researchers for all the people they've helped, without any actual guarantee that anyone is better off yet. For me this has been an humbling experience. Talking to Voz del Pueblo and the people of Bagaces has given me an important reminder;  if my goal as a scientist is to help people, the work doesn't end with a finished product in lab, but with a product in use.

Carter Merenstein

Reference:

Milton, A., Smith, W., Dear, K., Ng, J., Sim, M., Ranmuthugala, G., Lokuge, K., Caldwell, B., Rahman, A., Rahman, H., Sharim, A., Huang, D., and Shahidulla, S. 2007. A randomized intervention trial to assess two arsenic mitigation options in Bangladesh. Journal of Environmental Science and Health, Part A: Toxic/Hazardous Substances and Environmental Engineering, 42:12, 1897-1908