Environmental Engineering Reference
In-Depth Information
tions of benzoic acid esters and other compounds. European studies have
shown that they can be highly effective in controlling dust mite populations
and reducing allergen levels. However, studies showing concomitant reduc-
tions in asthmatic/allergic symptoms have not been reported.
Benzoic acid esters such as benzyl benzoate are commonly used as
acaricides in Europe. Health risks based on what is presently known appear
to be small, as benzoates are rapidly metabolized to hippuric acid and
excreted in the urine. Nevertheless, a major question remains as to the
advisability of using biocides whose safety is relatively unknown in indoor
environments, particularly when applied to bedding materials immediate to
one's breathing zone. Benzoic acid esters have not been approved for use as
acaricidal treatments by USEPA, though they are available from suppliers
of various allergy-related products in the U.S.
iv. Denaturants and other compounds. Though acaricides can reduce
dust mite populations and allergen levels on a long-term basis, they cannot
reduce allergen levels that are already present. As a consequence, commer-
cially available mite acaricides are formulated with denaturants that are
designed to degrade protein allergens, as well as with other substances that
prevent mite allergens from becoming airborne. The most commonly used
denaturant is tannic acid. It has been shown to be effective in laboratory trials.
The role of cockroach allergens in causing sensitiza-
tion, allergy symptoms, and asthma has only been elucidated in the past
decade. Few studies have been conducted to evaluate control techniques to
reduce exposure to cockroach allergens. Therefore, the best approach would
be to implement measures designed to control cockroach populations.
b.
Cockroaches.
i. Pesticides. Cockroaches in buildings are primarily controlled by
using pesticides. Prior to the year 2001, chlorpyrifos, in a product called
Dursban, was the most widely used pesticide for cockroach control. It has
since been replaced by other pesticides. Recommended application proce-
dures included spraying cracks and crevices, with particular attention to
kitchens and bathrooms because they are associated with the highest cock-
roach populations. Poisoned baits and integrated pest management proce-
dures are also recommended.
Cockroach populations are very difficult to control because of their high
reproduction potentials and favorable environmental conditions that are
common in low-income housing. Though cockroaches are known to infest
“relatively clean” houses, populations often become enormously high in the
relatively unsanitary conditions found in poor housing. In many cases sig-
nificant cockroach control on a sustained basis can only be achieved in
community-based programs.
ii. Integrated pest management. Integrated pest management (IPM)
is a systematic approach to controlling pests in individual environments. It
