Science-Based Recommendations to Prevent or Reduce Potential Exposure to Biological, Chemical, and Physical Agents in Schools

Article excerpt

Federal reports on environmental threats to children's health called for improved risk communication and environmental education. Communication of research results, environmental education, and recommendations must be based on the best available science, condensed and delivered to stakeholders.

Previous review papers examined studies and federal government reports, for time intervals ending prior to 2002, concerning relationships between education facility indoor air and environmental quality (IEQ), including adequate ventilation, and occupant health and productivity. (1,2) Except for work done in California and the Nordic countries, research on school IEQ related specifically to new or refurbished traditional school construction, or modular classrooms (portables), is limited.

This paper does not review quantitative and qualitative IEQ or quantitative and self-reported health symptom data. Instead, based on studies reported through fall 2003, school-based scientific literature was summarized to determine science-based, best practices recommendations to encourage school stakeholders to mitigate or prevent IEQ problems.

SEARCH PROCEDURES

Methodology

National Library of Medicine and University of California library electronic search engines and conference proceedings books were used. In addition, reference lists of papers and reports gathered were examined, as were government and professional association reports and school IEQ initiatives. The focus was on work available to the public in print, or by Internet, in English.

Primary keywords were school, school children, classrooms, portables or relocatables or modular classrooms, and attendance. Secondary keywords were IEQ topics covered: observed moisture damage; biological agents in air and dust (bacteria, fungi, allergens); toxic and odorous volatile organic compounds, including formaldehyde; direct measures and indicators (carbon dioxide) of ventilation; temperature and relative humidity (thermal comfort parameters); particles and dusts, and chemical residues like pesticides; carbon monoxide; persistent organic pollutants (polychlorinated biphenyls, phthalates); specific metals (arsenic, lead, mercury); asbestos; radon gas; lighting; and noise.

Peer-reviewed journals covered the period 1968 through fall 2003. Federal and California government reports available to the public were included. Case studies or informal consultant reports were excluded. Citations (n = 302) directly involving or highly related to school IEQ and occupant health, attendance, and productivity or performance were identified. References were tallied by category and IEQ topic (Table 1). National and international conference proceedings books searched (years available) included: Triennial International Conference on Indoor Air Quality and Climate (1990-2002); Triennial Healthy Buildings Conference (1997, 2000); Annual Conference, International Society of Exposure Analysis (2000-2003); and Annual Conference, International Society for Environmental Epidemiology (2002-2003).

Only peer-reviewed journal articles most directly justifying recommended best practices were referenced. This paper was not a meta-analysis. Studies reviewed (Table 1) did not represent every school, were not always representative of the geographical area studied, and sometimes described the school environment and potential exposures but not health outcomes.

CONCISE SCIENCE LITERATURE REVIEW

Most school IEQ studies, whether or not they examined qualitative or quantitative outcome measures, focused on specific agents.

Biological Agents

Leaks, moisture damaged materials, and bacteria, fungi, and allergens. Based on location on school grounds, weather, local irrigation, and crawl space cross-ventilation, classroom floors constructed of plywood, as well as roofs and inside walls, may be subject to water condensation build-up then damage. …