A new study has confirmed that bisphenol A leaches from those popular, colored plastic drinking bottles into people’s bodies.

A research team led by Karin Michels of the Harvard School of Public Health asked 77 students to consume beverages from stainless steel bottles for a week to rid themselves of BPA, which is normally cleared through the urine hours after consumption.

The students provided urine samples throughout the washout period and during the second week, when they consumed all liquids from polycarbonate bottles manufactured using BPA.

Week 2 specimens contained 69% more BPA than those from Week 1, and were equivalent to levels routinely observed in the general population. All other dietary habits were unchanged over the course of the study, leaving no doubt the BPA came from the bottles.

The study appears in Environmental Health Perspectives.

BPA makes those reusable plastic bottles more durable. It also prevents corrosion in the cans used for commercial soup and baby formula products.

Animal studies suggest that BPA causes developmental and endocrine problems. Recent human studies have linked urinary BPA concentrations to behavioral problems in children, reproductive problems, immune deficiency and an increased risk of diabetes and heart and liver problems.

Last year, amid growing concerns about its health effects, Canada proscribed the use of BPA in baby bottles.

The FDA says that BPA-laced products are safe, even for infants and children. In reaching that conclusion, it overruled its own advisory board which had chastised the agency for relying on industry-sponsored research in its analysis.

Steven Hentges, an American Chemistry Council official representing manufacturers, actually found the Harvard study results to be heartening.  To him, the study indicates “that even exclusive use of polycarbonate bottles does not lead to unusually high levels of bisphenol A in the urine.”

Boys born to women that had significant occupational exposure to hair spray while pregnant are twice as likely to develop a certain urogenital abnormality according to a study in Environmental Health Perspectives.

The abnormality is known as hypospadias, in which the urethra exits the body on the underside of the penis rather than at the tip. Hypospadias is generally corrected surgically during the first year of life and there are few long term sequelae after the repair.

In the general population, the incidence of hypospadias is 3 per 1,000 male births.

Paul Elliott and his team at Imperial College, London reported the association after using a retrospective, case-control study design to compare 471 hypospadias cases from the London area with controls randomly selected from a birth registry.

They obtained detailed histories regarding maternal age, education, folate supplementation, income, occupation, smoking and vegetarianism.

They also inquired about occupational exposure during pregnancy to toxins and carcinogens which are found in disinfectants, hair spray, paints, pesticides, plastics and printing ink.

The scientists believe the hair spray risk is related to phthalates, organic compounds that are often used in plastics manufacturing. Phthalates are also found in cosmetics, deodorants, fragrances, nail polish and hair products.

Phthalates disrupt androgen synthesis, and low levels of the male sex hormone are known to cause male reproductive tract abnormalities like hypospadias.

In case you were wondering, hair spray contains lots more inhalable toxins including polyvinyl alcohol, polyvinylpyrolidone and so on but wouldn’t you know it? These other ones aren’t toxic to male sex hormone synthesis, only the skin, eyes and cardio-respiratory system.