Monsoon Rains Drive Up Antibiotic Resistance Genes in Dehradun Urban Rivers

Monsoon rainfall significantly amplifies levels of antibiotic resistance genes in rivers flowing through densely populated areas of Dehradun, according to a recent scientific study. In May 2019, researcher Kenyum Bagra collected water and sediment samples along the Bindal Rao and Rispana rivers, two heavily polluted sub-tributaries of the Ganga. Rispana flows continuously all year, while the seasonal Bindal river was mostly dry upstream before reaching city settlements. Together, the two streams carry nearly 10 million litres per day of municipal wastewater in Rispana and about 18 million litres per day in Bindal. Both rivers eventually merge downstream to form the Suswa river, which is listed under the Namami Gange restoration project.

Pollution Sources And Monsoon Surge

Bagra observed solid waste and dead animals dumped directly into the rivers while children bathed just downstream. Her mentor Gargi Singh reported that the rivers suffer from widespread faecal and human-made pollution throughout their lengths. Although heavy rain normally dilutes water pollution, this study found that monsoon rainfall increased relative levels of antibiotic resistance genes by roughly 10 to 1,000 times. The heavy downpours wash accumulated street garbage, sewage, and overflowing septic tanks into the river channels. Sediment samples also contained lasting traces of key resistance genes like sulphonamide and tetracycline even after the monsoon ended. Analysis showed that pollution levels were uniform across both upstream and downstream locations, pointing to untreated municipal wastewater from open drains and septic tanks rather than just treated sewage plant outlets as the main source.

Public Health Risks

Local residents routinely use these contaminated waters for drinking, washing, and farming. Microbial expert Uli Klümper noted that seasonal events like floods drastically increase public exposure to resistant pathogens. Gargi warned that floodwaters carrying antibiotic-resistant bacteria worsen community health crises during waterlogging. Meanwhile, urban expert Nidhi Singh cautioned that upcoming construction plans like the 26-kilometre Rispana-Bindal elevated road project could heighten flood risks if natural drainage and waste management are ignored.