Of the 3,000 or so synthetic chemicals that are produced in quantities of more than one million pounds per year, fewer than 20% of these have any data available on kids. (Morrison, Heath & Jervis, 2008) As for the evidence that does exist, it’s not very encouraging, as we’ll show throughout this book. Here is a general overview of the effects of toxic exposures on children:

Stunted growth
A number of chemicals can interfere with normal growth, especially when exposure occurs during pregnancy, which is why babies with the highest in-utero exposures tend to be born smaller.

Childhood cancer
It’s believed that children accumulate as much as half of their lifetime cancer risk by age two, largely as a result of early chemical exposures. (More on this issue is discussed in our section on chemicals & cancer.)

Asthma & allergies
Chemical exposures have been known to trigger autoimmune disorders such as asthma or allergies. We’re not just talking about triggering an asthma outbreak; many things can do that. Chemicals can actually cause otherwise healthy children to become asthmatic.

Learning & behavioral disorders
Neurotoxins such as pesticides, lead, or mercury can lower IQ while decreasing inhibitory control and increasing rates of aggression. A variety of other chemicals can alter hormones in a way that alters mood or behavior. As a result, chemical exposures have been linked to conditions like ADHD or disruptive mood disorders.

Autism
While we still know very little about the root cause of autism, one factor that has withstood the test of time is chemical exposure, which remains a leading candidate of things that contribute to autism.

General health problems
In Japan, as many as 50% of babies are afflicted with eczema, which many believe is at least partially due to toxic exposures. (Weil, 1995) In fact, a number of skin conditions are related to chemical exposures. Other health problems in children – such as lung infections, hair loss, blood disorders, headache and low-energy or fatigue – can also be related to chemicals in their body.

The role that chemicals play in child health problems

Chemicals can cause these problems by triggering them directly or by creating the conditions that allow such problems to flourish. As Philip & Alice Shabecoff write, “a child might have a vulnerability to asthma or autism that might never develop without the toxic assault.” (2010, p. 34) Even when toxic exposures aren’t directly involved in creating a particular condition, they can make health problems in general worse by interfering with the functioning of a child’s immune response.