By Dr. Paul Ehrlich
We recently received this distraught letter:
“My son has dust allergies and asthma. I have been blaming myself for this because since my children were born I really let the house cleaning go. For many years I very rarely ran the sweeper or dusted. In your book, on pg. 211 it states at about 23 percent of homes have high enough levels of dust mite allergen to CAUSE asthma. So, that being said…a mother who doesn’t keep the dust in check can be to blame for causing her child’s asthma?”
First of all, thanks for reading the book in such detail.
Second, please don’t berate yourself. As a parent (and a grandparent) I know the tendency to blame oneself every time something goes wrong with a child, as well as take credit for everything that goes well. The real test of parenting skills and peace of mind is how we deal with the challenges once we know we have a problem.
Third, “dust mite central” is the mattress, and kids’ greatest exposure is during the eight hours a night they spend on it. You, and most parents, probably don’t “dust” the mattress, so you are not alone.
To the specifics of the way that passage is worded, there’s a great deal we don’t know about what “causes” asthma and allergies. In the introduction, we discuss the “pound of dirt” theory, which is also known as the “hygiene hypothesis.” This posits that by being too clean, we deprive the immune system of its natural targets and it goes looking for things that don’t bother most people. By this standard, you might think that a little extra dust around the house would be okay. But the hygiene hypothesis really pertains to parasites, which your immune system is trained to resist by producing an antigen called IgE. When there are no parasites, the same mechanism may attack certain proteins in otherwise harmless substances like those in dust mite feces, pollens, and so forth, resulting in allergies.
Maybe we should have said, “levels of dust mites high enough to TRIGGER asthma.” Certainly, most allergies occur in families where there’s a history of asthma. If any other family members—you, the grandparents, aunts or uncles—have allergies, this probably would have happened to your son regardless.
However, there’s also a growing body of research that indicates certain environmental irritants can alter the DNA of the lungs and change it from not being asthma prone to asthma prone. A study at Stanford compared adolescents in Fresno, where there’s a high level of diesel particulates in the air, to their counterparts in Palo Alto, where the air is cleaner. The Fresno kids with no family history of asthma now have lung tissue that genetically resembles that of kids with asthma in the family. This new science is called epigenetics. It’s the kind of research that should add new respect to the work of the EPA.
As we also say in the book—chapter 3—“particles penetrate deep into the airways and do microscopic damage to these tissues, this creates openings for allergens to do their mischief much the way a nail through your sneaker punctures your foot and creates an opening for tetanus. Tetanus germs are on your skin all the time, but they don’t penetrate without that nail. Heavy air pollution in one concerted exposure, as well as chronic low-level irritation, can damage the lungs to the point where true allergic asthma can take hold. The mast cells and others deep in the airways, having once been exposed, will become sensitized to certain allergens.”
The allergens in dust mites feces may function like other fine particles because (as we also say in the book) they “are the same size and shape as pollen grains so they are easily inhaled and drawn into the bronchial airways.”
In that case, given the fact that we spend so much time indoors, especially in the cold months with the windows closed, eight hours of every day in bed, maybe they do cause allergic disease.
Regardless, distraught Mom, you’re not the first to neglect your dusting, and you won’t be the last. Don’t take it so personally. It’s probably not your fault. Make sure you do the right thing for your child and the rest of your family from now on.