Cuba

Reducing exposure to mercury-tainted fish

Mercury-cell chlor alkali plants, which use mercury to produce chlorine and caustic soda, are a major source of mercury pollution around the world. For many years, the plant upstream of the city of Sagua la Grande in Cuba barely treated effluents before discharging them directly into the Sagua la Grande River. Few recent data exist, however, on the effects of mercury contamination on vulnerable groups such as pregnant or nursing women, women of childbearing age and children.

Researchers examined current methyl mercury levels in fish and sediment and also studied the risk perception of the population related to the mercury exposure. They discovered that mercury was accumulating in resident fish, particularly below the effluent discharge point of the local facility. In addition, total mercury concentration in sediment was above accepted levels in 80 percent of the stations sampled. And just over half of the population group studied were consuming unacceptably high quantities of methyl mercury in fish without a clear perception of the health risk.

The researchers shared these results with environmental and health authorities in the area, which led to collaborative strategies to reduce fish consumption and thus exposure to mercury. Daniel De La Rosa Medero also presented results in two academic articles and three international conferences. Moreover, part of the results of the project and other previous results earned them the National Prize for the Environment in 2009 from Cuba’s Ministry of the Environment.