Figure. 1.
A plastic bottle used to store water in it. Such plastic bottles may have very harmful compounds such as 'BPA' which disrupts endocrine or other system health. Such plastic compounds may cause early puberty, or excess, abnormal, long lasting menstrual bleeding in elder females.
This unhealthy compound competes with female, male hormones of human body.
Eating some foods such as 'bee honey' may decrease the unhealthy effects of plastic. Glass or metal water containers should be preferred over plastics if possible.

 

http://en.wikipedia.org/wiki/Bisphenol_A
Bisphenol A (BPA)

Bisphenol A is commonly found in plastic bottles (including many baby bottles), plastic food containers, dental materials, and the linings of metal food and infant formula cans. Another exposure comes from receipt paper commonly used at grocery stores and restaurants, because today the paper is commonly coated with a BPA containing clay for printing purposes.
It is a known endocrine disruptor, and "hundreds of studies published in the decade" have found that laboratory animals exposed to low levels of it have elevated rates diabetes, mammary and prostate cancers, decreased sperm count, reproductive problems, early puberty,obesity, and neurological problems. Canada recently announced it plans to phase out the use of bisphenol A in baby bottles and metal formula cans. in October 2008.
 In United States, Currently 11 states have banned BPA from baby bottles and children's sippy cups. The American Medical Association also recently announced its support of tighter restrictions on products containing BPA.