Imagine there is an outbreak of an infectious disease that could damage your child's brain for life. Wouldn't you want to know everything possible about how to prevent exposure to that disease? You'd surely make any sacrifice necessary to protect your child, and if your doctors weren't 100 percent certain of how this disease spread, you'd demand the best medical information available so that you could take precautions.
According to data recently released by the Centers for Disease Control, one in every 68 American children now has an autism spectrum disorder, an alarming 30 percent increase over 2012 estimates. This upward trend can no longer be rationalized as a product of "better diagnosing" -- environmental factors almost certainly are playing a role.
What could those factors be? Truth is, on average, Americans spend 90 percent of their day indoors. In today's homes, schools and workplaces, we encounter unprecedented concentrations of synthetic organic chemicals. In our tightly sealed, "energy efficient" buildings, these chemicals accumulate, and their concentrations can be two to five times higher, sometimes even hundreds of times higher, than in outdoor air. The production and use of synthetic organic chemicals skyrocketed after World War II. Sources include cleaning agents, fragrances, pesticides, furnishings, flooring materials, adhesives, paints, and other construction materials.
Already, there is ample evidence that environmental exposures can affect neurodevelopment. A growing number of published, peer-reviewed studies implicate flame retardants, vinyl flooring, proximity to freeway pollution, agricultural pesticides, coal-fired power plant emissions and other air pollutants including airborne heavy metals and possibly solvents as potential risk factors for ASD. Parents need help understanding which chemicals may be risk factors for their children's health. We are bombarded with chemical acronyms such as PAHs, PFOAs, PBDEs, BPA, phthalates and PCBs.
The vast majority of these chemicals entered our lives over the past 70 years. Our exposures have changed enormously, but our genes have not. Our bodies' elaborate detoxification systems are not equipped to deal with many of these novel chemicals. This situation is of greatest concern for children, infants and pregnant women, who tend to spend the most time indoors.
Indoor air contaminants are of special concern during critical windows of development -- particularly brain development. Embryonic brain development begins around three weeks post-conception, before most women even know they are pregnant. Families expecting a baby may unwittingly increase their exposures -- a move to a new house or renovation of a room often brings new furnishings, carpet, paints, fragrances and pesticides.
Doctors urge pregnant women to take their vitamins, get rest, and avoid alcohol, tobacco, and certain drugs. Just last year, obstetricians and gynecologists called for much-needed policy reforms and made sensible recommendations regarding environmental exposures. However, they failed to recognize and highlight the importance of the indoor environment.
Why don't doctors talk about indoor air? Because most doctors don't know about indoor air. For the past 20 years, I have been teaching medical students, and most are completely surprised to learn that the air inside their homes is very different from the air outside. I teach about indoor air by guiding students through an "environmental house call" that was designed for people with asthma. Interestingly, asthma and autism frequently occur within the same families.
We know that inhaled chemicals and particles can cause asthma in susceptible individuals. Little doubt remains that certain chemical exposures increase the risk of autism. Of course, more research is needed as is true for virtually every vital concern relating to human health, but do we need to know everything before we do something?
We may never have unassailable proof that certain exposures cause autism. Vested corporate interests may insist that more research is needed, but what we already know is frightening and the stakes are incredibly high.
We've developed a list of avoidable exposures, an approach we call the "personal precautionary principle during pregnancy" as described in a free online booklet: "Protecting Yourself and Your Family: How Exposures to Chemicals and Drugs Affect Our Health." Many of these exposures are things we bring into our homes. Some are clear risk factors (like pesticides), others are unstudied but eminently avoidable and unnecessary exposures like synthetic fragrances used in plug-ins, personal care products and fabric softeners. Because outdoor air contaminants inevitably migrate indoors, some exposures can be avoided by choosing not to live close to places where pesticides are routinely applied (agricultural fields, golf courses) or near heavy industry or traffic. Similarly, remember that idling the car or storing chemicals in an attached garage can contaminate the air in your home.
Our government is not going to regulate household exposures like these anytime soon. Indeed, we may never have sufficient data linking these exposures to adverse pregnancy outcomes. However, adults who have asthma or who are chemically intolerant/sensitive know firsthand the havoc these exposures can cause in susceptible individuals. Many parents already buy organic food for their children. Eating organic food can decrease exposures to pesticides. Some foods have more pesticide residues than others.
We've observed a clustering of what I call the "7As" (Autism, AD/HD, Asthma, Allergies, Autoimmune Disorders, Affective (mood) Disorders, and Addiction) among people who are chemically intolerant. The Quick Environmental Exposure and Sensitivity Inventory (QEESI) is a validated tool used worldwide to screen for chemical intolerance. It serves not only as a diagnostic tool but also helps people identify and eliminate their problem exposures. Everyone should take the QEESI (free online) to get an idea of how susceptible they may be, especially if their personal or family medical history includes any of the 7As.
Interestingly, Kanner described the earliest cases of autism in 1943, as WWII was underway and as petrochemicals were first being introduced. Today, petrochemical exposures are ubiquitous and appear to be playing a major role. The few studies cited here are just the tip of the iceberg.
So with all of this evidence at hand, why wouldn't concerned parents avoid potentially hazardous exposures prior to conception, during pregnancy and throughout infancy? We've outlined straightforward, actionable steps that may make a life-changing difference for the next generation.
Claudia S. Miller, M.D., M.S., is a tenured Professor in Environmental and Occupational Medicine and Vice Chair of the Department of Family and Community Medicine of the University of Texas Health Science Center at San Antonio (UTHSCSA).