Isotopes help trace the origin of urban water pollution in Mauritius (Chinese Edition)

Agricultural activities, illegal sewage disposal and animal breeding could be among the sources of nitrogen pollution in urban waterways around Port Louis, the capital of Mauritius, according to preliminary findings of an IAEAsupported study using isotopic techniques. In excessive levels, some compounds of nitrogen, such as nitrate, can find their way into urban waterways and pose a danger to people and the environment. In 2016, scientists began working with the IAEA to use isotopic techniques to assess the origin of nitrate pollution after authorities had detected nitrate contamination around Port Louis. Contaminants were found in streams and rivers, threatening protected areas, such as the Rivulet Terre Rouge Estuary Bird Sanctuary. Toxic algal blooms in the ocean caused episodes of fish kill, raising complaints among local fishermen. The sources for such pollution could have been manifold: inappropriate wastewater disposal systems from households, faulty septic tanks, industrial discharges, animal breeding and agricultural activities. Knowing who or what is responsible for nitrate pollution can help policymakers take informed action to protect rivers and groundwater.