chemicals that will linger in carpets and other parts of the household for a year or
more. Researchers found that 3 percent of ‘‘dislodgeable turf residues’’—the portion
of a pesticide that does not adhere to the turf—were tracked indoors. In homes with
carpeting, almost all of the pesticide became deeply imbedded carpet dust, where it
couldn’t degrade through exposure to sunlight, wind, rain, or soil microbes. Although
the investigation revealed that only 10 percent of the residue remained on carpet sur-
faces where it could easily contact human skin, previous research has suggested that
transport of pesticides from lawns and gardens presents significant risks of human ex-
posure, particularly for children.
In the study, researchers applied a pesticide formulation containing 2,4-D,
dicamba, and mecoprop (X-Gro Broadleaf Weed Killer) to sections of a lawn that
had not been treated with pesticides for at least ten years. Participants then walked
on the treated areas, staggering their times and walking in different areas so that most
of the treated ground was covered. They then either wiped their feet on a mat or
walked directly onto indoor carpeting, both of which had never been used before.
Researchers analyzed residues tracked onto the carpets as well as levels of dislodgeable
turf residues on the lawn.
Use of entryway mats reduced the level of pesticide residues on carpet surfaces by
25 percent and reduced carpet dust residues by 33 percent. Estimates were that 2,4-
D residues could remain in household carpet dust for up to one year after small turf
applications.^51
Another study found that up to 0.2 percent of the residues of two different herbi-
cides applied to a lawn were dislodgeable. Notably, the amount of residue that was
dislodgeable actually increased between four and eight hours after the application, as
the pesticide spray dried.^52
Another investigation revealed that 1.5 to 4 percent of residues of the insecticide
chlorpyrifos deposited on a lawn could come off the treated lawn onto shoes, skin, or
clothing.^53Home Garden vs. Commercial Use PesticidesPesticides for home garden use are not necessarily of low toxicity. Active ingre-
dients available to the gardener can be extremely toxic. The technical products of
strychnine (LD 50 ¼30–60 mg/kg) and Di-Syston (LD 50 ¼4 mg/kg) are readily
available at nurseries and garden centers. Anyone can buy them. The assumption that
the commercial applicator may use pesticides with more toxic active ingredients than
the gardener is wrong. Remember, it’s the dose that makes the poison.
Because of the small label size, home garden products may not list all of the plants
and/or pests for which the product may be registered for use. For example, one bottle
of ACME 25 percent EC, may be called ACME Fruit and Vegetable Insect Control,
while another bottle of ACME 25 percent EC may be called ACME Insect Spray.
Both may be basically the same product, but the plants and pests listed on the label
can vary greatly. This situation causes some confusion in pesticide applications and174 | Pesticides