An Intervention to Reduce Residential Insecticide Exposure during Pregnancy among an Inner-City Cohort

Insecticide use in inner-city communities in the United States is widespread, and resultant indoor exposures can be extensive (Fenske et al. 1990; Gurunathan et al. 1998; Lemus et al. 1998; Whitmore et al. 1994; Whyatt et al. 2003). In a recent study of African-American, Latina, and Caucasian mothers and newborns residing in East Harlem in New York City, 72% of subjects reported indoor insecticide exposure during pregnancy to control cockroaches and other pests. Maternal urine samples collected on delivery showed that 55% of subjects had detectable levels of 3,5,6-trichloro-2-pyridinol (TCPy), a metabolite of the organophosphate chlorpyrifos, and 37% had detectable levels of 3-phenoxy-benzoic acid, a metabolite of pyrethroid insecticides (Berkowitz et al. 2004). In our prior study of pregnant African-American and Latina women residing in northern Manhattan and the South Bronx, 85% of subjects reported that pest control measures were used during pregnancy, and 100% of participants had detectable airborne exposures to organophosphate and carbamate insecticides (Whyatt et al. 2003). In addition, these same insecticides were detected in 45–74% of blood samples collected from mothers and newborns at delivery. Insecticide levels in maternal and newborn blood samples were similar and highly correlated, suggesting that placental transfer of these compounds can occur (Whyatt et al. 2003). Further, the infants with the highest in utero exposure to the organophosphate chlorpyrifos had significantly lowered weight and length at birth and significantly poorer mental and motor development at 3 years of age (Rauh et al., in press; Whyatt et al. 2004). Experimental evidence has linked exposure to organophosphate insecticides during gestation or the early postnatal period to adverse neurodevelopmental sequelae in the offspring (reviewed by both Eskenazi et al. 1999; Landrigan et al. 1999). Although there is sufficient evidence documenting that residential insecticide use is pervasive among African-American and Latino populations residing in low-income urban communities in New York City, there is a paucity of data in the current literature describing methods to reduce residential insecticide exposure in these environments. Attempts have been made to determine the risk factors associated with pest infestation and resulting insecticide use. A survey of pest control measures used by residents of public housing in New York State conducted during 2000–2001 concluded that pest problems and insecticide use were related to housing disrepair and housing density (Surgan et al. 2002). Additional evidence has shown that cockroaches and other household pests thrive in multifamily dwellings where excessive moisture, cracks and crevices, and abundant food sources are present (Brenner et al. 2003). In our prior research, the proportion of women reporting that pests were sighted in the home, as well as the proportion reporting that pest control measures were used during pregnancy, increased significantly with the level of disrepair in the home (including holes and cracks in the walls and ceilings, water damage, leaky pipes, peeling or flaking paint) (Whyatt et al. 2002). Women who reported sighting pests in their home (primarily cockroaches and rodents) were significantly more likely to use pest control measures than women reporting no pest sightings (chisquare test, p < 0.001) (Whyatt et al. 2003). Therefore, effective interventions to reduce pest infestation levels and residential insecticide exposure must address aspects of housing quality such as unrepaired cracks and crevices, leaky pipes, and food sources. Integrated pest management (IPM) is considered an environmentally sustainable pest control strategy. It aims to reduce pest populations by identifying and understanding the biology and behavior of the insects and rodents; selecting and implementing a set of environmentally safe and effective control strategies; and monitoring the effectiveness of the strategies (Ogg et al. 1995). Techniques include building repairs to eliminate pest entry points and breeding sites, cleaning to remove pest food sources, and the use of low-toxicity, nonaerosol insecticides including baits, gels, and boric acid (Ogg et al. 1995). Interventions that have included IPM-like practices have been endorsed by the National Institutes of Health (1997), and several studies have documented the ability of IPM interventions to reduce pest populations, allergen levels, and asthma morbidity (Arbes et al. 2003; Brenner et al. 2003; Morgan et al. 2004; Wood et al. 2001). However, only limited data address the effectiveness of IPM interventions at reducing residential insecticide exposure (Campbell et al. 1999; Kass and Outwater, 2001). The current study is the first to use bio-markers and air monitoring to document changes in insecticide exposure after an IPM intervention. The IPM strategy used here was adapted from the Columbia Intervention to Reduce Indoor Allergens Study (Kinney et al. 2002). The aim of this study was to assess the feasibility of reducing prenatal exposures to pests and insecticides through an IPM intervention that included professional cleaning, building repairs, sealing pest entry points, professional insecticide placement, and one-on-one education.