In a study that was conducted to study the effect of social class on exposure to common water disinfectants it was found that wealthy people who choose to drink bottled water rather than water from public supplies may be no less exposed to potentially cancer causing water contaminants.
As part of the EPICURO national bladder cancer study, researchers from all over Spain quizzed 1,270 individuals about their water use and consumption in an effort to discover whether social class has any bearing on exposure to common water disinfection byproducts. High levels of trihalomethanes (THM), chemicals formed in chlorinated water, have been implicated as a possible risk factor for cancer and can be ingested through public drinking water supplies, or absorbed through the skin in baths, showers, and public swimming pools.
The CREAL (Centre for Research in Environmental Epidemiology) research team found that richer people with higher levels of schooling consumed more bottled water than those less educated. Dr Gemma Casta'o-Vinyals, who led the investigation, said, "People with more money and more education may think that they're reducing their risk of exposure to water contaminants by drinking bottled water. However, despite being apparently cleaner and taking more exercise a result of taking more frequent and longer baths, and using swimming pools more often they are actually increasing their risk of THM exposure.