Reporting of Toxicology

Stories must be turned in on a deadline, whether or not all sources were reached to present a balanced view. 

We will discuss risk communication further in chapter 9, specifically regarding risks of toxic effects related to chemical exposure. The examples below serve to illustrate the benefits, false alarms, and inflammatory and biased reporting that may occur in the media s coverage of toxicology. 

Although it is an excellent insecticide, the known effects on other species, such as raptors, were not acceptable for continued use in the United States and Europe because other alternatives were available. However, DDT is still used in developing countries because it is inexpensive and highly effective. Other alternatives are too expensive for these other countries to use. 

A more current example of how media reports can be accurate and helpful, and can reduce the incidence of illnesses, relates to contaminated spinach. In late 2006, a report was issued that people were getting ill from eating spinach used in salads. Many people got sick, and several died. It was later identified that Escherichia coli, one of the more common types of bacteria, was detected in the spinach and was responsible for the illnesses. After several months of study, the source of the contamination was traced to a single farm. The sanitation problem with this supplier was corrected, and the risk associated with eating spinach salads was eliminated. 

However, it is not always easy to differentiate between such stories with no background in toxicology, since media reports do not typically focus on the science. One of the goals of this book is to enable you to evaluate such stories and decide for yourself if there is a risk, and if such risk is high enough to warrant concern. The following examples represent false alarms and inflammatory and biased reporting by the media. 

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Therefore, if final, fully quality-assured individual study reports are not available at the time of IND submission, an integrated summary report of toxicological findings based... 

The most significant clarifications in the guidance document are (1) the explicit willingness of the FDA to accept an integrated summary report of toxicology findings... 

JECDB Database of chemical toxicity provided by Ministry of Health, Labour and Welfare, Japan. It contains reports of toxicological tests of compounds in the environment http //dra4.nihs.go.jp/mhlw data/jsp/SearchPageENG.jsp... 

Pesticides in the Diet of Infants and Children, Report of Board on Agriculture and Board on Environmental Studies and Toxicology, Commission on Life Sciences, U.S. National Research Council, National Academy Press, Washington, D.C., 1993, 386 pp. 

Pyridine Chronic Toxicology. AH mutagenicity tests have been negative and (1) is not considered a carcinogen or potential carcinogen. There have been no reports of adverse health effects on long-term exposure to (1) at low concentrations. 

Renhof M. 1984. Parathion-methyl (Folidol M actice ingredient) Study for embryotoxic effects on rabbits after oral administration. Bayer AG Institute of Toxicology, Wuppertal, West Germany. Unpublished Report No. 12907. 

Where sufficient toxicologic information is available, we have derived minimal risk levels (MRLs) for inhalation and oral routes of entry at each duration of exposure (acute, intermediate, and chronic). These MRLs are not meant to support regulatory action but to acquaint health professionals with exposure levels at which adverse health effects are not expected to occur in humans. They should help physicians and public health officials determine the safety of a community living near a chemical emission, given the concentration of a contaminant in air or the estimated daily dose in water. MRLs are based largely on toxicological studies in animals and on reports of human occupational exposure. 

A number of reports have established the presence of rodenticides in predators and scavengers found dead in the field (see, for example, reports of U.K. Wildlife Incident Investigation Scheme [WHS]). Brodifacoum, difenacoum, bromodiolone, and flo-coumafen have all been found, albeit at low levels in most cases (<1 ppm in liver). Sometimes, more than one type of rodenticide has been found in one individual. The toxicological significance of these residues will be discussed in Section 11.5. 

One of the few phytochemicals that has been subjected to the rigorous testing procedures required by food safety authorities is P-carotene, a naturally-occurring carotenoid that is also a pre-cursor of vitamin A in humans. It is increasingly used as a food colour since the food product can be claimed to contain all natural ingredients. For this reason, detailed toxicological studies were undertaken that enabled the Joint FAO/WHO Expert Committee for Food Additives (JECFA) to set an ADI of 0-5 mg/kg/bw/day based on a NOAEL of 50 mg/day and the application of an uncertainty factor of 10 (JECFA, 1974). This low factor was used because it was argued that the compound occurred naturally in food, that its use as a food additive would not lead to a substantial increase in the total amount normally consumed, and that there had been no reports of adverse effects in humans. The ADI would correspond to an acceptable intake in humans of up to 350 mg/day. 

NAS/NRC. 1989. Report of the oversight committee. In Biologic markers in reproductive toxicology. Washington, DC National Academy of Sciences, National Research Council, National Academy Press. 

ATSDR. 1993a. Technical report on ethylene glycol and propylene glycol. Agency for Toxic Substances and Disease Registry, Division of Toxicology, Atlanta, GA. 

CIIT. 1983a. 90-Day vapor inhalation toxicity study of hydrogen sulfide in B6C3Fj mice. Report to the Chemical Industry Institute of Toxicology, Research Triangle Park, NC, by ToxiGenics, Inc. CUT docket 42063. 

Zielhuis, R.L. (1972) Epidemiological toxicology of pesticide exposure report of an international workshop, Archives of Environmental Health, 25 399 05. 

OTHER REPORTS OF THE BOARD ON ENVIRONMENTAL STUDIES AND TOXICOLOGY... 

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