Table 1.

Research questions and study designs that employ environmental exposure measurements.

Hypothesis/question	Study design	Exposure measurement/scenario	Outcome/limitations
Are pesticides present in the residence?	Surveillance	Measurement: pesticides in air, water, soil, house dust, surfaces	Distribution of residential concentrations, predictive factors No direct link to exposure or health effects
What is the distribution of human exposures?	Exposure characterization	Media measurements, biomonitoring, and exposure factor characterization one or more times	Distribution of individual potential doses, estimation of high-end exposures, relatively small numbers because of resource limitations
Does an intervention reduce pesticide concentration in a residence?	Intervention	Paired samples before/after intervention	Reduction of environmental concentrations that likely influence exposure
What is the relationship between pesticide exposure and a health effect?	Epidemiology		Outcome: associations between pesticide exposure metric and health effect
	Cross-sectional	Concurrent potential exposure and outcome measurement	Limitation: potential problems with temporal sequence of exposure/effect
	Retrospective	Reconstructive analyses	Limitation: assumptions about past probability of contact and concentrations in the environment or body
	Prospective	Exposure measurement before disease; longitudinal measurements	Time varying exposures; cost, critical time period of exposure