A chemical used in baby bottles, plastic containers, dental sealants and canned beverages may cause cancer and infertility, according to mounting evidence. The synthetic chemical hormone is called Bisphenol A.

The Milwaukee Journal Sentinel reported recently that 88 percent of the medical studies it reviewed suggest that Bisphenol A causes harm. Many studies suggest the chemical especially at low levels, led to weight gain, cancer, hyperactivity and low sperm counts. Others found that it caused miscarriages and other reproductive failures, genital deformities, allergies and hyperactivity in lab animals. A 2005 study reported that Bisphenol A stunted brain development in lab rats. Only studies financed by the chemical industry concluded the chemical was safe. A new University of Missouri study revealed that of 115 studies of Bisphenol A, 94 found harmful effects. A National Institute of Health report found that the chemical compound could cause neural and behavioral damage to human fetuses in the womb and to children.

For many years, government regulators have sided with the chemical industry, maintaining that Bisphenol A is safe. However, in light of concern about possible harmful side effects, the government is currently reassessing. It will be weighing conflicting studies released by two scientific panels formed by the National Toxicology Program.

One panel, composed of 38 international experts issued a report finding that levels of the chemical among the population are higher than levels found to cause harm in lab animals. It also reported that these levels exceed what the Environmental Protection Agency considers safe.

Some scientists on the NTP’s non- expert panel expressed concern. Panel member Jane Adams, a professor at the University of Massachusetts will not allow her son to get dental sealants which contain the chemical. “I am concerned about this chemical. Much more research needs to be done,” she told the Journal Sentinel.

Simon Hayward, another member, stated that “When there is smoke, there is fire. There is definitely enough smoke to be worried.” Hayward is professor of prostate biology at the Vanderbilt University Medical Center.

Critics charge that federal policy on Bisphenol A was established more than 20 years ago before most studies were conducted.

The other panel, composed of 12 non-experts, ruled that the chemical may pose risks to children and fetuses, it was safe for adults.

In Canada, the federal government agency Health Canada plans to review scientific studies on Bisphenol A to verify its safety. A preliminary report is expected this spring and a final report in 2009. The Canadian government has placed Bisphenol A on a list of possible chemical hazards.

In the meantime, the British Columbia based Mountain Equipment Coop, a Canadian camping supply chain store and the Yoga-wear giant Lululemon announced recently it was pulling all polycarbonate bottled water and food containers from its shelves because of health concerns over Bisphenol A.

David Rosner, a public health historian at Columbia University, said that it is dangerous to allow widespread use of the chemical until its safety is verified. Consider what happened to lead and tobacco, he said. “Until we know that it is safe, it is more prudent to avoid it.”