A school-based strategy to assess children's environmental exposures and related health effects in economically disadvantaged urban neighborhoods

The School Health Initiative: Environment, Learning, Disease (SHIELD) study is a novel school-based investigation of children's environmental health i n economically disadvantaged urban neighborhoods of Minneapolis. This artic le describes the study design and summarizes lessons learned about recruiti ng and monitoring this historically understudied population. The SHIELD stu dy focused on measuring children's exposures to multiple environmental stre ssors [volatile organic chemicals (VOCs), environmental tobacco smoke, alle rgens, bioaerosols, metals, pesticides, polychlorinated biphenyls (PCB), ph thalates] and exploring related effects on respiratory health (e.g., lung f unction) and learning outcomes (e.g., standardized test scores, academic ac hievement). It involved intensive exposure monitoring, including environmen tal measurements inside and outside the children's schools and inside their homes, personal measurements with passive dosimeters worn by the children, and biological marker measurements in blood and urine. The SHIELD particip ants comprised a stratified random sample of 153 "index" children and 51 of their siblings enrolled in grades 2-5 at two adjacent elementary schools. The Minneapolis Public Schools (MPS) assisted with identifying, contacting, recruiting, and monitoring this population, which traditionally is difficu lt to study because families/children are highly mobile, speak a diversity of languages, frequently do not have a telephone, endure economic hardships , often do not trust researchers, and have a spectrum of unconventional lif estyles and living arrangements. Using a school-based approach, the overall SHIELD enrollment (response) rate was 56.7%, with a wide disparity between English-speaking (41.7%) and non-English-speaking (71.0%) families/childre n. Most children remained involved in die study through both monitoring ses sions and exhibited an acceptable degree of compliance with study protocols , including providing blood and urine samples. Results indicate that it is both practical and affordable to conduct probability-based exposure studies in this population, but that it is also important to improve our understan ding of factors (e.g., cultural, economic, psychological, social) affecting the willingness of families/children to participate in such studies, with special emphasis on developing cost-effective recruitment methods.