At this point, exposure to bisphenol A (BPA) has been linked to everything from breast cancer to obesity to heart disease. Now, new research suggests the plastic chemical's disruptive effects can even be seen in declining male fertility, reports Newsweek. In the study, published online in the journal PLoS Genetics, three strains of male mice were exposed to low or high doses of BPA for the first 12 days of their lives. Sperm counts were significantly lower in two of the three strains after BPA exposure. Taking the idea further, the researchers also transplanted BPA-exposed stem cells (that create sperm) into mice that hadn't been exposed. Even in these healthy mice, sperm production was low, suggesting the cells had been permanently damaged. This is especially pertinent because some studies show a general (but mysterious) decline in male fertility in the U.S. and other countries. Acting as an endocrine disruptor, BPA can mimic the functioning of estrogen in the body. A previous study indicated that men with higher levels of BPA in their urine also had lower sperm counts, so this new study could explain the mechanism behind that effect. However, there are still conflicting opinions about the safety of BPA and the processes by which we regulate it. Many BPA studies (including this one) have been done on mice, so although they can be scary, they aren't necessarily the best indication of what's happening in humans. Also, the FDA still says BPA is safe in food plastics at the current levels — although many suspect this is due to the agency's reliance on industry-funded research. Because BPA is so widespread in our society, trying to eliminate it from your life entirely seems like more trouble than it's worth. What we know about BPA-free plastics isn't exactly comforting, either. Still, we'll stick with our cute(r) glass water bottles for now — and we'll encourage anyone trying to conceive to do the same.