Laboratory tests on ten brands of bottled water purchased in nine states and the District of Columbia detected bacteria and 38 pollutants often found in tap water, some at levels no better than tap water, a study released Wednesday by the Environmental Working Group found.

The pollutants identified include common urban wastewater pollutants like caffeine and pharmaceuticals, an array of cancer-causing byproducts from municipal tap water chlorination, heavy metals and minerals including arsenic and radioactive isotopes, fertilizer residue and a broad range of industrial chemicals. Four brands were also contaminated with bacteria.