Water salinity and maternal health
Bangladesh stands at the forefront of climate change, with its coastal region witnessing dramatic sea-level rise over the last three decades. The resultant sea-water intrusion is increasing salinity in coastal drinking water with severe health consequences to surrounding populations. Our research team at Imperial College London and Bangladesh Center for Advanced Studies (BCAS) has found expecting mothers in particular, becoming acutely susceptible to the diseases of hypertension and (pre)eclampsia from this salinity exposure. This suggests that climate change is not only breaching our coasts, but is approaching the very shores of motherhood in the womb.
Extensive scientific research reveals that the earth's freshwater is among the first and most depleted resources impacted by climate change. The Intergovernmental Panel on Climate Change (IPCC) reports that groundwater, crop soils and many rivers are likely to become increasingly saline from higher tidal waves and storm surges as a result of climate change effects (IPCC 2007). Salinity along the Bangladesh coast has already encroached over 100km inland into domestic ponds, groundwater supplies and agricultural land, through the various estuaries and water inlets intertwined with major rivers.
Bangladesh's salinity intrusion threatens greater future incursion, for numerous reasons contentiously debated by scientists. These include reduced freshwater flows into the Padma River caused by the Farakka Barrage; climate change induced decreases of dry season rainfall, stronger and more frequent cyclones and sea-level rise; and intensified saltwater shrimp farming.
As we all know, coastal populations rely heavily on tubewells, rivers and ponds for their drinking water and cooking. Although the Food and Agriculture Organisation's (FAO) allowable water salinity level for human consumption is less than ½ gram per kilogram of water (ppt), river salinity in some coastal districts reaches as high as 4 grams in the rainy season and an alarming 13 grams per kilogram in the dry season (Center for Environmental and Geographic Information Services 2000). Seawater, which is extremely harmful for humans , contains 35 grams per kilogram of water. Approximately 20 million of the 37 million people living on these coasts (over 57%) are adversely affected by such salinity in their drinking water.
The causal relationship between excessive dietary salt intake and high blood pressure in adults and children is well established in public health. Over a decade ago, the World Health Organisation's (WHO) Public Health Initiative identified the health impacts of long-term consumption of highly saline waters as a priority for investigation. The government of Bangladesh and Caritas Development Institute (CDI) have identified a range of health problems with potential links to increased salinity exposure, including hypertension and miscarriage among pregnant women, skin diseases, acute respiratory infection and diarrhoeal diseases (Ministry of Environment & Forest 2006).
In 2008, our initial baseline survey in Dacope, Khulna found expecting mothers with high rates of hypertension and (pre)eclampsia, compared to non-coastal pregnant women. Hypertension is more commonly known as high blood pressure, while (pre)eclampsia is a multi-organ disorder characterised by high blood pressure, swelling of the body and convulsions. In both conditions, the expecting mother encounters impaired liver function and low blood count; the unborn baby risks growth retardation and premature birth; and both are at risk of death. Our study investigates a causal relationship between drinking water salinity and higher rates of hypertension and (pre)eclampsia (Khan et al, Lancet 2008).
Thus far, our epidemiological research results reveal a large segment of Dacope's population consuming 5 to 16 grams of sodium (a major component in salt) per day from drinking water alone, far exceeding the WHO's recommended allowable limit of 2 grams of sodium per day. The average level of sodium in urine among our sample of healthy pregnant women is 3.4 grams per day and in some women as high as 7.7 grams per day. More startling is the higher percentage of women diagnosed with hypertension and (pre)eclampsia in the dry season, when water salinity peaks. Our present data strongly suggests that these maternal health problems stem from higher salinity in drinking water, which our epidemiological study seeks to validate (Khan et al, EHP 2011).
Given Bangladeshi women's significant contributions to economic and social transformation, maternal health is fundamental to our country's sustainable human development. Yet despite improved health services for pregnant women, 1 in 21 women in Bangladesh (5%) dies from pregnancy and childbirth related causes, compared to 11 in 4,000 (0.3%) in developed countries (United Nations Population Fund 2002). Hypertension and (pre)eclampsia in pregnancy are major contributors to overall maternal morbidity and mortality in which 26,000 women die every year. About 700,000 women suffer from disabilities caused by such pregnancy and childbirth complications.
Although these maternal health consequences are profoundly disturbing, they are proven reversible in a relatively short time span through simple, affordable and sustainable adaptation measures. Pregnant women's awareness-building and health skills development on proper pregnancy care, water salinity health risks and safe drinking water practices, can enable more conscientious health and dietary choices to directly improve maternal health. Involving other key family decision-makers such as husbands and mothers-in-laws, as well as the community-at-large can substantially augment these health benefits. In our own experience, simply reporting maternal health research findings to target communities has motivated women to incorporate essential knowledge and preventive practices to better ensure their own health outcomes.
Increased community freshwater access and management for and by the coastal populations through rainwater harvesting and solar desalination, are viable, cost-effective alternatives for safe drinking water. Our abundant freshwater monsoons can be readily collected, stored and treated during the crucial dry season; while our tropical climate is well-suited to household solar distillation of contaminated water. These efficient and sustainable technologies are being attempted on a small scale; however, if replicated and fully-integrated into local cultures and practices, can become the primary (and replenishable) water sources for coastal communities.
Such common-sense interventions can directly empower and positively impact the health and well-being of our rural women. Furthermore, development studies have prominently shown that facilitating better maternal health outcomes improves children's health and education; and overall community well-being.
If we choose not to act, this looming health crisis of water salinity may be exacerbated to epidemic proportions by climate change induced sea-level rise. But if our local communities, government, NGOs, private sector and the general public decide to collectively tackle this environmental challenge, we can faithfully protect and foster human life in our coasts . . . and our mothers.
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