In a study by scientists from the Harvard School of Public Health (HPSH), volunteers were asked to use beverages in bottles made of polycarbonate (PC plastic) - a popular plastic bottle that was quite popular and Baby milk bottle - in 1 week. Two-thirds of them have increased amounts of bisphenol A (BPA) in their urine. It has been proven that BPA, a chemical commonly used to manufacture PC plastics and other plastics, disrupts reproductive function in animals and is linked to cardiovascular disease and diabetes. people.
This is the first study to show that the use of beverages contained in PC plastic bottles causes BPA in the urine to increase and suggests that the bottle containing BPA has released this chemical into drinks. If a person drinks a certain amount, the amount of BPA excreted in the urine will also increase.
BPA is in PC plastic bottles. This bottle is reusable and is a very popular container among students, campers and other target groups. They are also often used as baby bottles. In addition, BPA is also found in dental compounds, waterproofing agents and linings of aluminum food containers. (On the body of the bottle, box, PC plastic can be identified by the number 7 in the recycling symbol.) Many studies have shown that BPA is an endocrine disorder in animals, including the impact on sex maturation, altering the growth and tissue organization in the mammary gland, reducing the number of sperm in the offspring. This substance is the most harmful in the early stages of development.
According to Karin B. Michels, associate professor of epidemiology at Harvard School of Public Health and Harvard Medical School, senior author of this study, 'We found cold drinks used in PC plastic bottles. in 1 week increases more than 2/3 of BPA in urine. If these bottles are heated, like in the case of baby bottles, the BPA content is significantly higher. This is very worrying because babies are particularly vulnerable to the risk of endocrine disorders caused by BPA. '
The research team is headed by Jenny Carwile, a doctoral student in epidemiology, Harvard and Michels School of Public Health, who conducted research on Harvard students in April 2008. In the first 7 days of the experiment, 77 volunteer students only used cold drinks in bottles made of stainless steel, to minimize the amount of BPA. For the next 7 days, two volunteers were given two PC bottles of plastic to each volunteer and suggested to use drinks in these two bottles. After each stage, the volunteers' urine samples were taken for research.
The results showed that volunteers' BPA concentrations rose 69% during the period of using drinks in PC plastic bottles. (The study author notes that BPA levels in the student community are similar to those in the American community in general.) Previous studies have shown that BPA can partially dissolve from plastic bottles. PC on the item is contained; however, this is the first study to show a corresponding increase in BPA levels in the human body.
One of the strengths of this study, according to the author, is that students use drinks in bottles under normal use conditions. Moreover, they do not use dishwashers to wash bottles, nor pour hot water into bottles. High temperatures increase the content of BPA melted from bottles so if you drink hot drinks in PC plastic bottles, BPA in urine may have increased very high.
Canada ordered a ban on the use of BPA in the production of baby bottles from 2008. Some manufacturers of PC plastic bottles have voluntarily removed BPA from their products. More and more evidence proves the potential harmful effects of BPA on humans, so the author of this study argues that further research on the effects of BPA on newborns and up is needed. Reproductive dysfunction as well as breast cancer in adults.
'This study comes at a critical time, because many states in the United States are deciding whether to ban the use of BPA in the production of milk bottles for sippy children and cups (the type of water in which the water cannot be filled) even if the cup is upside down - ND). While previous studies have shown a relationship between BPA and adverse health effects, this study adds a missing part of the problem - whether it's a PC plastic bottle. important factor causing BPA levels in the body ' - Carwile said.
This study received support from the Center for Environmental Research - Harvard University, Institute of Environmental Health Sciences and National Key Biological Analysis, School of Environmental Health - School of Public Health Harvard and Environmental Epidemiology Training Program.
References:
Carwile et al.Use of Polycarbonate Bottles and Urinary Bisphenol A Concentrations.Environmental Health Perspectives, May 12, 2009;DOI: 10.1289 / ehp.0900604