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Growing Up Toxic:Chemical Exposures and Increases in Developmental Disease
by Travis Madsen, Frontier Group and Elizabeth Hitchcock, U.S. PIRG Education Fund
A growing body of scientific evidence shows that the widespread use of chemicals in our society harms our health and the health of our children. The incidence of many serious health problems – including premature birth, learning disabilities, behavioral disorders, asthma and allergies, early puberty, obesity, diabetes, reduced fertility, and some types of cancer – shows links with exposure to chemicals that can interfere with the process of growth and development.
In this report, we tell the story of the insidious impact of toxic chemicals, from the plastic ingredient bisphenol A to pesticides, drawing on evidence from more than 200 peer-reviewed scientific papers. Over and over, manufacturers have introduced new compounds into commerce – and only later do scientists discover these substances accumulating in our bodies or contributing to major health problems. Moreover, once the impact of a toxic chemical on our health becomes clear, barriers built into our chemical regulatory systems often prevent meaningful action. Manufacturers become tied to the profits chemical sales can generate, and exposure to offending substances continues.
It is unacceptable to use human lives – even unintentionally – as a giant uncontrolled experiment. Until our society reforms the way we regulate chemicals, this story will be rewritten time and again. The United States should remove the most dangerous substances from commerce and require manufacturers to ensure that the chemicals used in everyday products are safe for our families and our communities.
We are constantly exposed to toxic chemicals.
- When scientists look, they can find more than 100 potentially dangerous industrial chemicals and pollutants in the body of the average U.S. resident.
- These chemicals include substances banned in the United States since the 1970s, such as DDT and PCBs. Other widespread contaminants include plastic additives such as bisphenol A and phthalates, flame retardant chemicals, pesticides, non-stick chemicals used in cookware, carpet or clothing, and toxic metals such as lead.
Exposure to toxic chemicals comes from many sources.
- The food we eat exposes us to chemicals – such as DDT, PCBs, PBDEs, dioxin, and certain pesticides – that accumulate in fatty tissues and concentrate as they climb up the food chain.
- Food containers from soup cans to baby bottles contain Bisphenol A which leaches into the food stored within. Some food wrappings contain phthalates.
- Our homes, from the materials used to build them to the furniture and appliances, contain toxic chemicals such as phthalates (in the vinyl flooring), stain-resistant perfluorinated chemicals (in the carpet), lead (old paint), and brominated flame retardants (in pillows, seat cushions and certain electronic devices).
- Objects in the home – or products used indoors – can release toxic chemicals which then accumulate in household dust, which people breathe, ingest, or absorb through their skin.
- Personal care products such as shampoos, lotions, deodorant and nail polish can contain phthalates that may be absorbed through our skin.
Chemical exposures can interfere with key stages of development, at levels commonplace in people today. Overwhelming evidence from studies with experimental animals and with people show links with many serious conditions throughout a human life.
- According to the U.S. National Academy of Sciences, just under half of all pregnancies in the country end in miscarriage or produce a child born with a birth defect or chronic health problem. Chemical exposures could be a factor. For example, laboratory mice exposed to bisphenol A develop chromosome sorting errors in their eggs that could lead to miscarriage or conditions like Down syndrome. The effect persists even into grandchildren that were not directly exposed.
- Premature birth has increased more than 30 percent in the United States since 1981. A variety of chemical exposures could be linked to this trend. Studies show that women exposed to higher levels of phthalates and some pesticides are more likely to give birth early or to give birth to smaller babies.
- From 2003 to 2007, the number of parent-reported diagnoses of attention-deficit hyperactivity disorder (ADHD) in their children increased more than 20 percent, with as many as one in ten children now affected. A variety of chemical exposures could be linked to this trend.
- The prevalence of children with asthma has more than doubled since 1980. Children and adults in high-phthalate homes and workplaces are more likely to develop asthma symptoms. Some phthalates can cause hyperactive immune responses when rubbed on mouse skin.
The timing of exposure is critically important. Often, exposures during key windows of development in the womb or early in life are most damaging.
- Windows of vulnerability when a key developmental process is vulnerable to disruption sometimes last only a matter of days – and damage can take the form of increased susceptibility to disease which might not become apparent until later in life. For example, experiments with rats reveal that exposure to a hormonally active chemical on gestational day 17 can cause birth defects in the reproductive system – but not if the exposure happens on gestational day 16.
Exposure to mixtures of chemicals can cause greater damage than exposure to individual substances alone.
- Traditionally, toxicologists have studied chemicals one at a time to determine how hazardous they are. This approach is likely to underestimate the potential danger because we are never exposed to just one chemical at a time in the real world. Scientists are discovering that mixtures of active chemicals – especially when they act on the same underlying mechanism of life – can have a greater impact together than any individual chemical alone.
Reducing our exposure to toxic chemicals can improve our health.
- Since lead was banned in gasoline in 1976, the number of children with high blood lead levels has declined from 88 percent to just 1.4 percent, reducing developmental brain damage. Scientists estimate that the health benefits of this action produced more than $300 billion in value for the United States economy through 1999.
The United States should remove the most dangerous chemicals from commerce and require chemical manufacturers to demonstrate that their products are safe before widespread use. Chemical regulatory reform should:
- Empower regulatory agencies to restrict or ban the manufacture and use of chemicals that pose potential dangers;
- Require chemical manufacturers to prove that each chemical they market is safe; and
- Ensure public access to information on chemicals and their potential hazards through mandatory reporting requirements, including product ingredient disclosure.