Health literacy involves basic reading and numeracy, which allow a person to function as a health care consumer, by reading, understanding, evaluating and using information in health documents. For thirty years, the gap between the reading level of most of the public, eighth grade, and the reading level of most written health information, above the tenth grade, has been perceived to prevent people from comprehending health instructions or educating themselves about health conditions. This study examined comprehension of health materials, using print environmental public health information about relatively obscure aspects of arsenic and ultraviolet light contamination. Specifically the research question was "to what extent are print materials for environmental health promotion comprehensible by the target audience of readers at the eighth grade reading level?" This study tested a hypothesis that materials written at the seventh grade level would be more comprehensible than those written at the twelfth grade level for individuals with an average reading level. Materials were located, assessed for reading level, rewritten to the seventh grade reading level, and vetted by environmental health experts. The mean reading level of the participants was eighth grade. The study was conducted with a pretest / posttest design with follow up interviews to asses some participants' perception of the reading materials and test. Data was analyzed using repeat measures ANOVA and content analysis. Contrary to anticipated results, the study showed that when people with average reading ability read twelfth grade material, they were able to comprehend it as well as they did seventh-grade material. Two follow-up interviews provided anecdotal evidence indicating people with an average reading level would not voluntarily choose to read the twelfth grade material. Although the results of this small exploratory study found individuals, with average reading levels, can read and comprehend written information about environmental health topics, health literacy professionals cannot stop being concerned about the perceived mismatch between the reading levels of American adults and reading levels of environmental health information. It is important to undertake additional studies to better understand how much of an encumbrance hard-to-read information may be placing on individuals with a need to know about environmental hazards and their health. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]