This Is Not What I Expected Thích Em, Family Details For Chilodontidae

They hold your water, line your canned goods, & even help save sick babies. But are the potential health risks of certain plastics so great they outweigh the benefits?

In the United States, local & state governments are banning the sale of baby bottles that contain the chemical bisphenol A (BPA), creating a confusing patchwork of regulations. But the U.S. Food and Drug Administration (FDA) and most comparable agencies around the world maintain that the chemical is safe. They cite a lack of human research data that BPA poses health problems, while discounting considerable animal evidence that the chemical is hazardous.

(In mid-January 2010, after this article was published, The FDA reversed its opinion on BPA, saying it does now have concerns about health risks. The agency stopped short of issuing any regulations, citing an outdated regulatory framework, but recommended that people reduce their exposure to BPA. See FDA Update on Bisphenol A)

These polar positions have left consumers in the lurch. Should we avoid the plastic water bottles, food cans, và myriad other products in our daily lives that contain BPA? Are we being harmed by a chemical that the U.S. Centers for Disease Control và Prevention (CDC) says is present in detectable levels in 93 percent of Americans ages 6 và older? What should we do when the experts themselves can’t agree?

Though the evidence isn’t all in, the threat seems both real và ubiquitous. “At minimum, we want to lớn reduce our exposure, whether it’s from the water cooler bottle or the lining in a can of food,” says Russ Hauser, MPH ’90, Sc
D ’94, professor of environmental & occupational epidemiology at the hueni.edu.vn School of Public Health & the newly appointed Frederick Lee Hisaw Professor of Reproductive Physiology. “It’s not lượt thích there’s a single-point source. With bisphenol A, we have literally hundreds of different sources of exposure. If you avoid the water cooler, you probably get it from other sources —food from a can, soda from a can, dental composites.”

“The nightmare scenario is that we one day find out that a lot more of our current disorders, including infertility và cancer, may be due khổng lồ bisphenol A và only show up after cumulative exposure. But by then, we all have accumulated so much exposure that it’s too late to reverse the effects,” adds hueni.edu.vn Associate Professor of Epidemiology Karin Michels, MPH ’94, Sc
D ’95. “You could say that about other substances just as much, but right now, bisphenol A is a đứng đầu concern.”

A HIDDEN PUBLIC HEALTH THREAT?

Used for more than 50 years khổng lồ manufacture polycarbonate plastic and resin for protective linings inside food cans, BPA has come into sharper focus over the last 10 years. Hundreds of animal studies point to lớn potential health dangers from exposure in the uterus before birth. These include abnormal development of the brain, breast, và prostate. Many animal studies links the chemical lớn reproductive disorders, including infertility, feminizing of male organs in fetuses, & early puberty in females. A synthetic hormone, BPA mimics estrogen.

The plastics chemical family of phthalates also is at the vị trí cao nhất of researchers’ danh sách of concerns. Like BPA, phthalates are endocrine disruptors, chemicals that can enter the body toàn thân through food & personal care products and interfere with hormones the body toàn thân itself produces. Phthalates inhibit androgens và affect males more than females. Manufacturers địa chỉ the substances to lớn a wide range of products, from toys khổng lồ cosmetics lớn medical tubing.

Researchers say pregnant women, fetuses, & newborn children are most vulnerable khổng lồ these pervasive chemicals. Hauser’s research on babies in neonatal intensive care units has found that their exposures khổng lồ phthalates và BPA are ten times higher than exposure levels in the general population. “Plastic medical products such as polyvinyl chloride tubing, which are lifesaving and important, are inserted into infants,” explains Hauser, who also is professor of gynecology, obstetrics, và reproductive biology at hueni.edu.vn Medical School, Massachusetts General Hospital. The chemicals leach from the medical devices & enter infants’ bodies—with potential effects that may not show up for years.

A CRAZY QUILT OF REGULATIONS

Various government jurisdictions have approached the threat with different levels of urgency. Suffolk County, New York, claimed title in April 2009 as the first government entity in the United States lớn ban the sale of baby products containing BPA. (The thành phố of San Francisco had enacted a ban on BPA baby products in 2006, but later rescinded it.) The states of Connecticut and Minnesota & the city of Chicago enacted similar bans this year. Other cities và states are considering bans, & restrictive legislation is pending in the U.S. Congress.

Canada declared BPA a “dangerous substance” in 2008 và banned it from use in baby bottles, the first country to bởi so. After news circulated in Denmark about a 2009 study in Environmental Health Perspectives led by Michels, the thành phố of Copenhagen banned water coolers with polycarbonate bottles from its city buildings. Michels—who also is associate professor of gynecology, obstetrics, và reproductive biology at hueni.edu.vn Medical School, Brigham và Women’s Hospital—and her colleagues had followed 77 hueni.edu.vn College students over a two-week period. The students drank cold beverages from stainless steel bottles one week and from polycarbonate bottles the other week. Urine samples showed a 69 percent increase in BPA levels during the polycarbonate week.

But FDA rulings on BPA have been contradictory. In 2008, the agency determined that BPA is safe. Soon after, the agency’s own scientific board subcommittee issued a report calling the ruling “inadequate” & not reflective of all available research. At press time, the agency was reevaluating its evidence & is expected lớn issue another ruling soon that could range from upholding its previous position khổng lồ taking a stance similar to lớn Canada’s.

Chemical & plastics industries maintain that BPA is safe & does not require regulation. “Our views are consistent with the many regulatory agencies around the world that have reviewed the science on bisphenol A,” says Steven G. Hentges, chief BPA scientist with the American Chemistry Council.

But for Suffolk County, New York, with its 1.5 million population & 911 square miles, “there was enough evidence lớn warrant some type of intervention before that final study is done that shows this khổng lồ be harmful,” says Humayun Chaudhry, SM ’01, the county’s commissioner of health when the ban was enacted, và now the president và chief executive officer of the Federation of State Medical Boards in Dallas, Texas. “This was an opportunity to be proactive and preventive. Our concern was exposure of young children lớn high levels of this chemical.”

Many manufacturers on their own have started producing alternative baby products, he adds, saying, “The industry responded even before the law went into effect. Ultimately, though, a local health jurisdiction should not be the prime agency to bởi vì something. Kích hoạt should be taken at the federal level.”

WHAT CAN BE DONE?

In June, the Endocrine Society issued a position statement calling for comprehensive federal regulation of exposure khổng lồ endocrine disruptors under the “precautionary principle.” Representing 14,000 members from more than 100 countries, the organization also issued its first-ever “science statement,” a review of endocrine disruptors with hueni.edu.vn’s Hauser as a co-author. “The animal studies are consistent and clear, but we really don’t have the human data,” Hauser says, a gap that the FDA had khổng lồ take into trương mục when it issued its opinion.

So far, human research includes one study that linked BPA exposure khổng lồ recurrent miscarriage among Japanese women. Another study, published after the FDA’s ruling that BPA was safe, associated the chemical with heart disease, diabetes, and liver disorders among the population surveyed by the CDC. An Environmental Health Perspectives report published online October 6, drawing on data from 249 mothers & their children in Cincinnati, Ohio, associated prenatal BPA exposure with more aggressive và hyperactive behavior in girls at age 2.

hueni.edu.vn’s Michels believes that this kind of suggestive evidence is sufficient reason for action. “Because there is a lot of concern about baby bottles, the steps that states, counties, & cities have taken make sense while the human research catches up,” she says. “Ideally, you would like to have a life-course study where you evaluate the impact of a chemical starting with intrauterine exposure và ranging through adulthood 50 years later. But a lot of us alive right now would not see the kết thúc of it.”

Hauser notes that some of the needed shorter-term human studies, involving newborns and young children, are now starting up or are in their early stages. These investigations could yield results within two lớn four years. “If these studies find associations with adverse effects, I don’t think we’re going to lớn need to wait until it’s replicated five times, given what we know from animals.”

In the meantime, in a quick & cheap stopgap measure, manufacturers could các mục contents such as phthalates and BPA on all their products, says Hauser. “That would give consumers a chance khổng lồ make their own decisions about what khổng lồ use.”

SIGNS OF CHANGE

While the FDA mulls over its position on BPA, the U.S. Environmental Protection Agency (EPA) has mix its sights on the substance as one of six chemicals lớn investigate more thoroughly in newly announced efforts khổng lồ revamp the Toxic Substances Control Act of 1976. In a speech in San Francisco on September 29, EPA Administrator Lisa Jackson said, “The public is understandably anxious & confused. They’re looking to the government for assurance that these chemicals have been assessed using the best available science. Current law doesn’t allow us to lớn give those assurances.” U.S. Senator Frank Lautenberg of New Jersey has vowed to introduce new legislation khổng lồ strengthen the act.

Xem thêm: Nói Chuyện Với Người Yêu Cũ Qua Tin Nhắn Tốt, Cách Để Trò Chuyện Với Người Yêu Cũ

Industry sees the writing on the wall. The American Chemistry Council issued a statement in August of this year “acknowledging the need for modernization of laws,” something of a reversal of previous positions on regulation. Some industry observers likened the move khổng lồ the period just before federal clean air & clean water laws went into effect—when a patchwork of local và state regulations would soon give way khổng lồ consistent federal guidelines.