The carcinogenicity of dietary acrylamide intake: a comparative discussion of epidemiological and experimental animal research.

Since 2002, it is known that the probable human carcinogen acrylamide is present in commonly consumed carbohydrate-rich foods, such as French fries and potato chips. In this review, the authors discuss the body of evidence on acrylamide carcinogenicity from both epidemiological and rodent studies, including variability, strengths and weaknesses, how both types of evidence relate, and possible reasons for discrepancies. In both rats and humans, increased incidences of various cancer types were observed. In rats, increased incidences of mammary gland, thyroid tumors and scrotal mesothelioma were observed in both studies that were performed. In humans, increased risks of ovarian and endometrial cancers, renal cell cancer, estrogen (and progesterone) receptor-positive breast cancer, and oral cavity cancer (the latter in non-smoking women) were observed. Some cancer types were found in both rats and humans, e.g., endometrial cancer (observed in one of the two rat studies), but there are also some inconsistencies. Interestingly, in humans, some indications for inverse associations were observed for lung and bladder cancers in women, and prostate and oro- and hypopharynx cancers in men. These latter observations indicate that genotoxicity may not be the only mechanism by which acrylamide causes cancer. The estimated risks based on the epidemiological studies for the sites for which a positive association was observed were considerably higher than those based on extrapolations from the rat studies. The observed pattern of increased risks in the rat and epidemiological studies and the decreased risks in the epidemiological studies suggests that acrylamide might influence hormonal systems, for which rodents may not be good models.

Risk assessment of peak exposure to genotoxic carcinogens: a pragmatic approach.

Short-term exposures to relatively high concentrations or doses are a regular cause of concern. Since carcinogenicity is often of great personal and social relevance the question arises whether short-term exposure (1-10 days) to a carcinogenic substance may contribute to tumour development and, if so, whether this contribution to the cancer risk can be quantified. The present object was to explore the possibility of a pragmatic estimation of the cancer risk of peak exposure to a genotoxic carcinogen relative to the cancer risk of the same cumulative dose of this carcinogen distributed over lifetime. A report published by the Health Council of The Netherlands served as point of departure. Published data strongly suggests that short-term or single exposure can indeed give rise to tumour formation in animal experiments. The application of a dose-rate correction factor (DRCF), defined as a factor by which the tumour incidence caused by a specific dose of a chemical carcinogen at low-dose rates is multiplied to derive the tumour incidence at high-dose rates, appears to be a feasible approach. Theoretical models calculated maximum values for the DRCF of up to seven for a young child acutely exposed to an initiator or first-stage carcinogen. A maximum value of 8.3 was calculated from animal experiments. A decision tree is presented which allows the pragmatic assessment of the carcinogenic risk following short-term exposure to genotoxic carcinogens. It is recommended to validate this decision tree with model-substances.

Risk assessment of deoxynivalenol in food: concentration limits, exposure and effects.

The mycotoxin, deoxynivalenol (DON), is produced world-wide by the Fusarium genus in different cereal crops. We derived a provisional TDI of 1.1 microg/kg body weight (bw) and proposed a concentration limit of 129 microg DON/kg wheat based on this TDI and a high wheat consumption of children. In the period September 1998-January 2000, the average DON concentration in wheat was 446 microg/kg (n = 219) in The Netherlands. During this period, the dietary intake of DON exceeded the provisional TDI, especially in children. Eighty percent of the one-year-olds showed a DON intake above the provisional TDI and 20% of these children exceeded twice the provisional TDI. Our probabilistic effect assessment shows that at these exposure levels, health effects may occur. Suppressive effects on body weights and relative liver weight were estimated at 2.2 and 2.7%. However, the large confidence intervals around these estimates indicated that the magnitudes of these effects are uncertain.

The wreckage of the oil tanker 'Erika'--human health risk assessment of beach cleaning, sunbathing and swimming.

In December 1999 the oil tanker 'Erika', carrying approximately 30 tons of heavy fuel oil, wrecked before the coast of Brittany (France), polluting the local beaches and rocks over a distance of some 500 km. Also numerous birds were affected. During the first months of 2000 the coastal area and many birds were cleaned. The health risk for people involved in these cleaning activities and for tourists was evaluated with emphasis on the carcinogenic properties of this oil. The outcome indicates that the risks were limited to people who had been in bare-handed contact with the oil. Firstly they had an increased risk for developing skin irritation and dermatitis, however, these effects are in general reversible. Secondly they had an increased risk for developing skin tumours, but since the dermal contacts with the oil were of relative short duration, this risk is considered to be very limited.