Pesticides in indoor and outdoor residential dust: a pilot study in a rural county of Taiwan

Abstract

We conducted a pilot study to examine pesticides in dust of homes in a rural county of Taiwan. A total of 56 homes of pregnant women were included in the study. Indoor and outdoor dust was collected by a vacuum sampler and a dustpan/brush set, respectively. Nine pesticides were selected for analysis on gas chromatography-mass spectrometry with the detection limits being 0.088 ng/g or lower. The most detected pesticides were cypermethrin and chlorpyrifos, which appeared in 82.7 and 78.8% of indoor samples and 48.2 and 39.3% of outdoor samples, respectively. The detection of pesticides from indoor and outdoor dust, however, was not consistent, indicating different sources of pesticides. In addition to those two most detected, permethrin, prallethrin, and tetramethrin, which were common ingredients of insecticide products for indoor use, were also frequently found in indoor dust, suggesting that indoor use of such pesticide products may have been a major source. Fewer pesticides were found in outdoor dust, but the outdoor detection of chlorpyrifos was significantly associated with farms present inside the circles with radii of 50 and 100 m surrounding the homes (P = 0.021, 0.016). It is suggested that pesticide drift from agricultural areas to residential environments may have occurred. No seasonal effect on distribution of pesticides in dust was found, indicating that pesticides could be routinely used in Taiwan regardless of season. Compared with other international studies, this study shows relatively high levels of chlorpyrifos but low levels of pyrethroids (i.e., cypermethrin), reflecting a different pattern of pesticide use in Taiwan. Further studies need to be warranted for a better understanding of exposure to pesticides and the associated health effects.

Relationship between Organophosphate and Pyrethroid Insecticides in Blood and Their Metabolites in Urine: A Pilot Study

“…This result of PYRs suggests that the subjects should have been exposed to insecticides environmentally more than via the dietary ingestion route because all but cypermethrin are used for environmental sanitation only. The finding of a high detection rate and high mean concentration of cypermethrin is consistent with our previous work indicating cypermethrin as the most frequently detected PYR in house dust [38]. Prallethrin is commonly known for the active ingredient of electric mosquito incense, which customers usually use overnight for mosquito prevention.…”

“…The lower detection rates shown in the U.S. studies are rational because the ban of chlorpyrifos in domestic use became effective in 2000. A similar comparison result was made in our previous work [38], demonstrating relatively low levels of chlorpyrifos in the dust of U.S. houses compared to our Taiwanese data. As chlorpyrifos and terbufos have been banned for domestic use respectively in the U.S. and in China and European Union [41], exposure to OPs should be of concern in Taiwan.…”

“…The high detection rate of terbufos suggests that these subjects may have been exposed to insecticides originating from nearby agricultural areas environmentally, or simply via dietary digestion of contaminated vegetables. The former scenario is improbable, because no environmental terbufos was detected from indoor or outdoor dust in these homes, as shown by our previous work [38]; thus, the latter (dietary digestion) was the most likely answer. This inference is reasonable because agricultural produce is regulated to contain no or limited insecticide residue, which would usually build up low levels of insecticides in the human body; in addition, dietary ingestion is a constant exposure route, and thus the detection rate of insecticides could be within a moderate range.…”

“…In Taiwan, chlorpyrifos is used for both agriculture and environmental sanitation, while terbufos is only used for agricultural purposes [38]. The high detection rate of terbufos suggests that these subjects may have been exposed to insecticides originating from nearby agricultural areas environmentally, or simply via dietary digestion of contaminated vegetables.…”

Daily Intake Estimation for Young Children’s Ingestion of Residential Dust and Soils Contaminated with Chlorpyrifos and Cypermethrin in Taiwan

“…With such substantial consumption in quantity, residues of insecticides present in residential environments are nearly inevitable. A pilot study conducted in Taiwan has demonstrated high detection rates of chlorpyrifos and cypermethrin in house dust, reflecting frequent use of insecticides in the homes [2]. Residues of insecticides in the home environment serve as a potential health threat to young children, because their hand-to-mouth behaviors may enhance the non-dietary ingestion exposure to insecticides [3].…”