Are environmental toxins to blame for autism and ADD?
Are environmental toxins to blame for autism and ADD?
Monday, January 25, 2010
Parents of a certain age remember the slogan, "a better world through chemistry," in the 1950s and '60s, which promised new compounds as the key to a life of luxury in a carefree future.
A couple of generations down the gene pool, those parents are mostly grandparents and contemporary science is telling us that the chemical cures to our ills and irritations may be worse than the nuisances they were created to eliminate.
Making connections between our chemical frenemies and runaway rates of developmental disabilities isn't just for tree-huggers and hippies anymore. The link between toxins and the American pandemic of autism, attention deficit disorders and allergies is moving into the mainstream, say agencies supporting people with disabilities. These agencies are trying to spread the word with pamphlets warning women of childbearing age about chemicals hiding in their cupboards. They're sponsoring teleconferences highlighting medical breakthroughs about the way everyday substances alter the workings of our brains and our genes.
Dr. Peter Orris, who co-authored an American Medical Association resolution calling for federal reform on chemicals, says experts are just beginning to connect the dots between chemicals and developmental disabilities.
"Many substances that we previously thought were toxic only at higher levels, we are beginning to understand now in fact incorporate in people's bodies," Orris said in a recent interview with Chicago Parent. Orris is professor and chief of service in Environmental and Occupational Medicine at the University of Illinois Medical Center at Chicago School of Public Health.
This generation of children is exposed to an enormous number of toxins before they are even born, says Cindy Schneider, medical director of the Center for Autism Research and Education and the mother of two children with autism.
"Doctors and medical researchers are just now beginning to realize the cumulative effects of the many, many toxins to which we are exposed to each day," she says.
But purging chemicals from life can be a hard pill to swallow.
The culprits are so much a part of our everyday world, it boggles the mind to imagine how we could cope without them. How are we going to keep our clothes fresh without the dry cleaners and fabric softeners? Despite efforts of the past couple of years to wipe out lead-laden toys, they keep rearing their heads. Wood in some furniture, decks and swing sets continues to be treated with arsenic.
The dinner table is teeming with toxins. Our favorite crystal wine glasses, the wicks of the candles and imported ceramic bowls are delivery systems for lead even before we put mercury-laden fish on them. Switching to chicken? There's a 50-50 chance it's tainted with arsenic. And when you eat with amalgam dental fillings, you're shooting mercury into your brain with every chew, though experts disagree on how much.
Try stepping out into the garden once the weather warms. You'll breathe in the fertilizers growing your grass and weed killers keeping those botanical bad boys at bay. And if Fido has been squirted with a flea-repelling capsule, don't turn to him for comfort.
Isn't the EPA making sure we don't encounter chemicals in amounts that can harm us? Not really, Schneider and Orris say. Business interests commonly influence the levels of toxicity categorized as safe by federal regulatory agencies, Orris says. Lead, for example, is known to be toxic at well below current blood levels, Schneider adds.
"More and more I find it disconcerting because, always, the EPA guidelines are a compromise between what's good for people and what's good for the economy and what's practical for business, and sometimes, we lose, frankly," Schneider says.
Taking on toxins
Cathy Ficker Terrill, of Elmhurst, took on the overwhelming task of detoxifying her family's living space. When Terrill started tracking her 4-year-old daughter Beth's meltdowns, she saw how they came in tandem with home projects: When they resurfaced the driveway, when they scrubbed with ammonia-based cleaners, when the lawn service sprayed the lawn.
Terrill and her husband took extreme tactics. They built a new house as a fortress against Beth's neurological-based allergens. The house has all-wood floors and low-chemical paint that was baked on the walls to minimize chemical emissions. The family stopped using perfumed personal products, banished pesticides and fertilizers from the yard and stopped cleaning with chemicals. Now, they just use vinegar and baking soda.
Terrill, a past president of the Illinois chapter of the American Association on Intellectual and Developmental Disabilities, took the podium at last fall's Public Health Forum on Toxic Chemicals, Disabilities and Policy Solutions in Chicago. The forum was co-sponsored with the Illinois Public Interest Research Group.
She wishes she would have stepped off the chemical carousel
before she got pregnant. She believes her daughter's allergies were
borne of things Beth experienced in the womb-and the science is on
her side. She and her daughter are now experimenting with
bio-monitoring, which measures body toxins.
"It's time we should look at the pollutants we put in our bodies," she says.
Summing it up
"Synergistic toxicity" is how Schneider sums up typical contact with common chemicals. "One plus one plus one may add up to 300, 3,000, 3 million," she says.
The equation starts with genetic programming, crafted by the body of a mom and dad who have lived in close contact with questionable chemicals for much of their lives. Add exposure to toxins in the womb, where unborn babies can be harmed by small amounts of toxins that would have little or no impact on children or adults. Then figure in the multiple chemical risk factors kids encounter as an infant and toddler.
Other things people put in their bodies-what they eat and medications they take-play a big role in how well the system can cope with the harmful chemicals it comes up against. Inherited genetic ability to fight off chemicals will be a driving factor in the future for studying risk factors for autism and other neurological disorders, Schneider says.
On her most dangerous list are a trifecta of prolific toxins-lead, mercury and pesticides.
Every week, new science links the increase in exposure to toxic chemicals to serious chronic health problems. Yet, the vast majority of the 80,000 chemicals uses in commerce have never been screened for human health impacts, according to information from the AAIDD.
Cathy Ficker Terrill says she figured it out the hard way.
"Parents of children with learning disabilities need to take a long hard look at their environment and the chemicals that are all around us and start making some critical connections," she says.
Lead: It could be in your tap water
The federal government banned lead paints decades ago. Yet
lead's legacy of poison still lingers in places people never
suspect, including in the water faucet.
Water in more than 800 cities has lead levels exceeding EPA action levels and more than half of all U.S. towns have lead-lined or lead-soldered pipes, Schneider says.
"There are many, many parents who are just simply drinking and cooking with tap water that's supposed to be safe," she says.
Scientists know lead can cause mental retardation, developmental delays, microcephlia, irritably and tremors, miscarriages and still births. Lead is especially brutal on young children and fetuses, which absorb four times the amount of lead as adults. Lead concentrations in the fetus are the same as in the mother and can linger as long as 20 years in bone tissue.
Inside developing brains, lead tangles crucial nerve circuits in the prefrontal cortex, hippocampus and cerebellum, "similar to what is seen in Alzheimer's," Schneider says.
Children with blood lead content at "acceptable" levels had lower IQs, she says. Reading and writing scores were about half those of other students. It compromises functions in the prefrontal cortex of the brain, spawning impairments in impulse and mood control.
Studies show higher rates of autism in kids with higher lead levels. In screening every child she treats for mineral deficiencies, Schneider finds this to be a common thread in children with autism.
Pesticides: Newborns are testing positive
About 90 percent of American households use pesticides to chase pesky bugs and critters out of their houses and yards. In a recent analysis, Schneider found that 20 out of 20 newborns tested positive for organophosphate pesticides.
Studies show that prenatal exposure to pesticides are at the root of memory deficits, reaction time, childhood hypertension and delays of about four years in understanding spatial relationships like elementary geometry. A growing body's ability to clear itself of toxins from pesticides depends largely on its ability to generate a certain enzyme tagged the PON1, which is also involved in using good cholesterol and reducing inflammation.
Some genetic codes give a child a very robust ability to clear pesticides, while others inherit very weak pesticide-fighting gene programming. In her research, Schneider found, children with autism tended to inherit the latter gene configurations at a higher than expected rate in the U.S. To make matters worse, the latest studies show, babies don't make any of this pesticide-protecting enzyme at all during their first year and a half.
Doctors now link poor PON1 enzyme production with autism in the United States. Some autism experts believe today's babies are inheriting weak PON1 producing genes because of parents' lifetime of exposure to harmful chemicals.
Mercury: It's in fish, vaccines, even mascara
By now, every parent knows that eating too much fish puts people and fetuses at risk for mercury poisoning. Yet as sushi grows in popularity among young adults, 8 percent of women of childbearing age are eating mercury-laden sushi at higher than safe levels set by the EPA. Eating three servings a month of any fish multiplies the body's mercury level by four.
Mercury also comes into our bodies through substances as deceptively benign as fabric softeners, mascara, fungicides in paint made before 1990 and even in common dental fillings. Most families have no idea that, when a compact fluorescent light bulb breaks, they need to open the windows and leave the house for 15 minutes.
"There's a certain protocol for cleaning them up and it certainly doesn't involve a vacuum cleaner," Schneider says.
When the U.S. government outlawed lead paint in 1978, manufacturers started using mercury instead. It was perfect for drying up mold and mildew for bathrooms, basement and kitchen walls. Though the U.S. government banned mercury-laced paint in 1990, there are still "many, many homes with that kind of paint to this day," Schneider says.
Levels of mercury in moms with fillings in their teeth made with amalgam-the most commonly used fillings' substance, containing a mixture of mercury with at least one other metal-match exactly with hair samples in infants. Normal chewing in one day can pump as much as 43 micrograms of mercury straight through the olfactory canal and into the brain through the skull.
Exposure to mercury is medically linked to violent allergic
reactions, like those sweeping through the latest generations.
Where lead levels in moms and babies are about the same, fetal
levels of mercury often outpace those of the mother.
"For some reason, mercury actively crosses the placenta beyond the rate you would expect," Schneider says.
The solution is to opt for ceramic dental fillings, but it can
be a costly choice because most dental insurance plans still only
pay for mercury-based amalgam.
Mercury may be the most controversial of common toxins because of its use in childhood vaccines. Over the past decade, mercury contact in vaccines has dropped, but the H1N1 and seasonal flu vaccines include up to 25 micrograms of mercury.
"Although I'm thrilled they decreased the amounts of Thimerosol used in vaccines, I think until we get to 0, we will not have solved the problem,' she says.
And doctors' post-vaccination orders can compound the problem. Acetaminophen-commonly recommended after injections-actually boost mercury's toxicity, making it harder for the body to clear toxins, Schneider says.