Linda Tollefson

The use of epidemiology, scientific data, and regulatory authority to determine risk factors in cancer of some organs of the digestive system: 2. Esophageal cancer☆

The epidemiologic aspects of esophageal cancer are well known. The extreme geographical variations in incidence of the disease, the variability in the sex ratio, and the secular trends have been described frequently. The etiology of cancer of the esophagus is known to be complex and composed of multiple factors, those caused by the environment being of greatest importance. The disease preferentially attacks groups with a low socioeconomic status or those hindered by poverty. The esophageal cancer belt has been frequently studied to provide clues to the etiology of esophageal cancer but no definite culprit has yet been found. The majority of the factors so far implicated in cancer of the esophagus appear to act directly on the esophagus rather than systemically. This is an unusual situation in that it enables the disease to be prevented by primary means. There appears to be an enormous disparity in the etiology of the disease among various countries. This disparity may be more apparent than real if the epidemiologic data are interpreted to mean that there is a two-stage process involved, with multiple etiologies for each stage. If we assume that nutritional deficiencies, even subtle ones, predispose the esophagus to influence by carcinogenic substances, the geographic differences fade. Nutritional deficiencies can develop by chronic alcohol use as well as by poverty and lack of an adequate food supply, but diet does not explain the whole picture. External carcinogens are necessary to effect the end result. The culprit may be tobacco in one culture and fungal elements in another. The South African studies which showed an association with tobacco and not alcohol could be explained if we assume that the populations nutritional deficiencies already predisposed the esophagus for the effect of an external carcinogen, thereby making alcohol usage superfluous. It would be helpful if the relationship between esophagitis and nutritional status were elucidated and if it were determined that the condition could be improved or eliminated by dietary factors. The association between nutrition and esophagitis may suggest methods of primary prevention of esophageal cancer and provide a chance of lowering the incidence of this deadly disease.

Monitoring adverse reactions to food additives in the U.S. Food and Drug Administration

Technological advances in food science have resulted in the development of numerous food additives, most of which require premarket approval by the Food and Drug Administration (FDA). Concomitant with the benefits of these additives, such as extending the shelf life of certain food commodities, is the potential for various risks. These potential risks include the possibility of the consumer experiencing an adverse reaction to the additive. In order to ascertain the character and the gravity of alleged adverse reactions to food products which it regulates, the FDAs Center for Food Safety and Applied Nutrition has developed the Adverse Reaction Monitoring System (ARMS). This postmarketing surveillance system for food additives is designed to analyze consumer reports of adverse reactions in order to alert FDA officials about any potential public health hazard associated with an approved food additive, and to delineate specific syndromes which may lead to focused clinical investigations. To date, among the products routinely monitored in the ARMS, sulfiting agents and the artificial sweetener aspartame have generated the largest volume of consumer reports describing adverse reactions. An overview of the analyses of the sulfite and aspartame adverse reaction reports is presented, along with a description of the mechanics of the postmarketing surveillance system, and a detailed discussion of its limitations.

Recalls of foods and cosmetics by the U.S. food and drug administration

Recalls of foods and cosmetics from the marketplace are an expeditious and effective method of removing violative products, particularly those that present a danger to health. Recalls are undertaken through a cooperative effort by industry and the U.S. Food and Drug Administration (FDA). Foods and cosmetics recalled from the period 1 October 1991 through 30 September 1992 were reviewed to determine the kinds of products recalled and the reasons for recall. A total of 230 recalls, involving 569 foods and cosmetics, occurred during the study period. Twenty-eight percent of the recalls were designated class I, defined as a situation in which there is a reasonable probability that the use of, or exposure to, a violative product will cause serious adverse health consequences. The problems for which foods or cosmetics were most often recalled were misbranding and microbial contamination (37% and 25% of recalls, respectively). A recognized illness or injury was reported to have occurred in association with 32 food products and one cosmetic. This study indicates that recalls of foods and cosmetics are common and that various groups, including industry, consumers, state regulatory agencies, and the FDA, recognize problems leading to recall.

Control strategies for Salmonella enteritidis in five countries

Abstract World Health Organization (WHO) surveillance data on human salmonellosis for 1979–1987 indicate that Salmonella enteritidis (SE) isolation rates are increasing in the Americas and Europe. SE outbreak investigations indicate a strong 3ssociation between the consumption of raw or lightly cooked eggs and human illness. Summaries are presented of programmes to control SE in egg production for five nations: Canada, the Netherlands, Sweden, the UK and the USA. These nations were selected because they had established Salmonella surveillance systems and different rates of SE infection. Although all five nations instituted controls for SE at three principal points in egg production (poultry feed, breeding flocks and egg production), the programmes have distinct characteristics. For context, data obtained from the WHO on reported SE isolates in humans in each of these nations are presented. SE control programmes were influenced by the human isolation rate, government funding and industry support. SE programmes in the five nations are becoming more alike, in that cooperative efforts between government and throughout industry are being promoted. Motivation to establish non-regulatory controls for SE is strengthened by regulatory controls that are available if needed.

Use of epidemiology data to assess the cancer risk of 2,3,7,8-tetrachlorodibenzo-p-dioxin

Most countries have assessed the human cancer risk of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) by extrapolating from animal data. The 1600-fold variation for acceptable intakes estimated by the Americans, Canadians, and Europeans, however, indicates a large scientific uncertainty about TCDD toxicity. Regulators are attempting to use human epidemiology data to eliminate some of the limitations inherent in using animal data to quantitatively assess cancer risk in humans, particularly now that techniques for measuring TCDD levels in adipose tissue and serum are available. This paper presents an overview of the major epidemiologic studies that associate cancer with TCDD exposure. The actual exposures experienced by the study populations are emphasized. The TCDD serum levels of the Seveso, Italy, residents and of the NIOSH Dioxin Registry participants indicate that these populations hold the best promise for future assessment of the human carcinogenic risk of dioxin. Based on the animal data, however, the calculated risk from these exposures is still moderate compared with high background cancer incidence present in most industrialized countries.