By Emilio Godoy
BPA is an organic compound in polycarbonate plastics used to produce baby bottles, water bottles, can linings, sports equipment, dental sealants and kitchen appliances. It has been shown to leach into canned or bottled food or beverages, which means consumers ingest it in low doses.
It is an endocrine disruptor – a chemical that interferes with the body’s hormone functions – and has been found to have negative effects on human health. Research shows that endocrine disruptors pose a greater risk during prenatal and early postnatal development, when organ and neural systems are forming.
In spite of the scientific evidence, “no measures are being taken against bisphenol A” in Mexico, Isabel Hernández, a scientist at the Laboratory of Female Reproductive Toxicology, in the Centre for Research and Advanced Studies (CINVESTAV) at Mexico’s National Polytechnic Institute, told Tierramérica.
Since 2010, Hernández has led a research project on oocyte quality in female mice exposed to oral contact with BPA. Preliminary results show a decline in oocyte fertilization rates in laboratory animals.
The final phase of the research project is to study the possible effects of BPA on ovulation in mice. “It looks like there is no effect, but we need to examine hormone levels,” she said.
The study, due to be completed in February 2012, will be published in scientific journals and presented at the annual meeting of the U.S.-based Society of Toxicology, in March 2012 in San Francisco, California.
BPA, produced by corporations like Bayer and Dow Chemical, has already been banned or restricted in Brazil, Canada, Costa Rica, Turkey and the EU, raising fears among experts and activists that the banned products may have been sent to developing countries like Mexico.
In the United States, the Food and Drug Administration (FDA) will decide by April 2012 whether it will restrict BPA in food packaging, while the Environmental Protection Agency’s (EPA) attempt to include BPA and other substances on the Chemicals of Concern List has been blocked by the White House.
But at least eight states have already passed laws banning BPA from baby bottles and other children’s products, and a number of states are studying similar measures.
In Mexico, the closest thing to regulations are the Ministry of Labor and Social Welfare’s rules on health and safety in workplaces where potentially hazardous chemical substances are handled, transported, processed or stored.
“BPA should be banned. It’s part of the chemical cocktail served up to us in processed foods. The industry argues that ingested doses are low and do not pose any risks,” Alejandro Calvillo, head of El Poder del Consumidor (Consumer Power), a consumer rights group, told Tierramérica.
Mexico produces more than four million tons of plastic a year, mainly plastic bags, film wrap and bottles, according to industry statistics.
Two recent studies have addressed the pollution caused by BPA in Mexico.
Six researchers at the Autonomous University of San Luis Potosí, the Potosí Institute of Scientific and Technological Research and the Spanish University of Granada published a paper in April in the Bulletin of Environmental Contamination and Toxicology titled “Phthalates and Bisphenols Migration in Mexican Food Cans and Plastic Food Containers”.
They found a range of endocrine disruptors, including BPA, in canned vegetables, baby bottles and microwaveable food containers. “The analyzed samples included 24 cans of vegetables, 4 plastic microwaveable containers, 12 plastic yoghurt or cream food containers and 6 baby bottles…All the sample items were bought in supermarkets in the northern state of San Luis Potosi,” the study says.
“Endocrine disruptors were found in all samples. Bisphenol A (and five other chemicals among those analyzed) were found in baby bottles and microwaveable containers,” it adds.
“The importance of these findings is that plastic food containers (for) yoghurt and cream are re-used in Mexican households to keep and to reheat food in microwave ovens, exposing the food to high temperatures and hence, increasing the risk of migration (of BPA into foods),” the authors stress.
Another study, “Bisphenol A exposure in Mexico City and risk of prematurity: a pilot nested case control study”, published in the Environmental Health journal in October 2010, was the first to document the presence of BPA in urine samples from pregnant women in the third trimester of pregnancy.
BPA was detected in 80 percent of the 60 spot urine samples collected from 2001 to 2003, according to the paper by nine experts from the National Institute for Public Health in Mexico, the Universities of Michigan and Harvard in the United States, and the U.S. Centers for Disease Control and Prevention (CDC).
“This study provides preliminary evidence that pregnant women who delivered at less than or equal to 37 weeks of gestation and prematurely (less than 37 weeks) had higher urinary concentrations of BPA compared to women delivering after 37 weeks,” the paper concludes.
In November 2010 a panel of experts convened by the World Health Organization (WHO) and the Food and Agriculture Organization (FAO) decided not to recommend new limits or restrictions on the use of BPA A because of the uncertainty surrounding its potential adverse health effects.
The EU, which banned the manufacture and import of baby bottles containing BPA this year, set the safe daily intake level at 0.05 mg per kg of bodyweight.
Calvillo of Consumer Power recommended “informing the public and confronting the authorities with the problem so that they assume their responsibilities, respond to concerns and enter into debate on these issues.”