A study by the Harvard School of Public Health (HSPH) found that participants who drank from polycarbonate bottles – which is the plastic commonly used in disposable plastic water bottles, other plastic drinking bottles, and baby bottles – for just one week showed a two-thirds increase in their urine of the chemical BPA.[8] Exposure to BPA has been shown to interfere with reproductive development in animals and has been linked with cardiovascular disease and diabetes in humans.