Life-History Calendars

Both pilot studies used LHCs to collect data on human–chemical interactions over the lifespans of participants in single sittings. In both populations, exposure to harmful substances over the lifespan was a common experience. In agricultural workers, the LHC was focused on collecting occupational histories and sequences of agrichemicals used. In IPWIDs, the LHC was focused on injection practices and sequences of substances injected. While the focus and scope of both studies varied, there were similar questions asked regarding the process of LHC administration. In both studies, participants were asked nine identical questions regarding the process of LHC administration (further described below in “Assessments by LHC administrators” and “Assessments by LHC participants”). In both studies, a semi-structured interview guide facilitated the completion of a baseline survey, the LHC, and a follow-up survey. The LHC for agricultural workers was administered using paper only, with 1 participant completing an electronic LHC to test-run the modality of administration. The later study conducted in IPWIDs randomized participants to either an electronic (n = 20) or paper-based (n = 20) modality of administration. Paper-based LHCs in both studies appeared on two 30 “×42” pieces of paper. Colored pencils were used to delineate phases of life described by the participant, and pens were used to annotate responses on the LHC forms. The follow-up survey contained questions for both the interviewer and participant regarding the LHC activity that just took place.