Search PubMed⌕ Search

Biomedical subjects

E J Calabrese

Publications and source records attributed to E J Calabrese.

At least 19 recordsLinked to original sources
PubMed1992

The Council for Health and Environmental Safety of Soils.

The Council for Health and Environmental Safety of Soils (CHESS) was organized in 1987 to develop a consensus soil risk assessment methodology to be used as a framework for establishing standards for soil contamination to protect the environment and public health. The wide range of contaminating substances of possible health concern in soil is affecting land use and development, causing excessive economic expenditures, and the regulatory approaches for control are disperse. The International Society of Regulatory Toxicology and Pharmacology agreed to sponsor the Council and through a Governing Board composed of experienced scientists from the federal government, state departments of public health and environmental protection, academia, and the private sector including industry and environmental organizations. The Board was created to support the goals of CHESS, its mode of operation, and to establish funding policies and directions. A technical council agreed to develop a peer-reviewed consensus methodology to assess public health risks from contaminated soil by technical committees composed of recognized experts in the area of soil contamination and other relevant disciplines. This methodology would then be made available to federal and state agencies, the private sector, and the scientific community at large. After extensive study, a final decision was made to develop a decision-tree framework to be used at the state and local levels for application to all types of soil contamination. Following extensive studies it was agreed the ubiquitous nature of petroleum contamination in soil has direct and immediate public health implications and CHESS therefore directed its first efforts to this area.(ABSTRACT TRUNCATED AT 250 WORDS)

Environmental Pollution↗
PubMed1992

Does the animal-to-human uncertainty factor incorporate interspecies differences in surface area?

Risk assessment practices for noncarcinogens typically employ an uncertainty factor (UF) for animal-to-human extrapolation when defining acceptable levels for humans based on animal studies. EPA has interpreted the use of this factor as addressing interspecies differences due to dose normalization via surface area (exposure-dose relationships) and to innate differences in species susceptibility (dose-response relationships). Thus EPA has concluded that dose normalization via surface area is not necessary when using animal studies to define acceptable levels for noncarcinogens for humans. In this report we challenge this position on both theoretical and practical grounds. It is recommended that the UF for animal-to-human extrapolation for noncarcinogens in the risk assessment process and the technique for dose normalization be considered distinctly.

Animals↗
PubMed1992

Distinguishing outdoor soil ingestion from indoor dust ingestion in a soil pica child.

This paper represents the first quantitative attempt to distinguish the amount of outdoor soil ingestion from indoor dust ingestion in a soil pica child. Based on a methodology using a comparison of differential element ratios it is estimated that the predominant proportion of the fecal tracers were from outdoor soil and not indoor dust origin. The methodology employed can be utilized on a broader scale to assess the relative amounts of soil and dust consumed by individuals.

Child↗
PubMed1992

Effects of joint exposures to selected peroxisome proliferators on hepatic acyl-CoA oxidase activity in male B6C3F1 mice.

The interaction potential of peroxisome proliferators of similar and dissimilar structure was examined in B6C3F1 mice. Mice were fed diets containing varying concentrations of ciprofibrate (Cipro), clofibrate (Clof) or di(2-ethylhexyl)phthalate (DEHP), or combinations of Cipro and Clof or Cipro and DEHP for 4 d. Induction of peroxisomal beta-oxidation, measured by increased acyl-CoA oxidase activity, was used as the endpoint for analysis. An additive response occurred following joint exposure to the structurally related compounds Cipro and Clof, whereas a possible synergistic response occurred at low dose combinations of the structurally dissimilar Cipro and DEHP. These findings represent the first report assessing the in-vivo interaction potential of structurally similar and dissimilar peroxisome proliferators and provides insight into the dose-response nature of joint exposures to certain non-genotoxic carcinogens.

Acyl-CoA Oxidase↗
PubMed1992

The interactive effect of chlorine, copper and nitrite on methaemoglobin formation in red blood cells of Dorset sheep.

Simultaneous exposure to chemicals which can oxidize the haemoglobin of the red blood cell to methaemoglobin is common. Although the effects of some of these agents have been documented individually, little research considers the interactive effects. In-vitro experiments on the treated blood of female Dorset sheep assessed the interactive capacity of chlorite, copper and nitrite to affect methaemoglobin formation. All combinations of doses which produced 2.5, 5, 10% methaemoglobin were tested in all possible combinations (a total of 80), as were the controls. This included data on each chemical alone, each two-way combination and the three-way combination. The response is largely additive (the sum of the individual effects) except for one of the two-way interactions, chlorite/nitrite (P less than .01), which showed antagonism. Chlorite may oxidize nitrite which could explain the less-than-additive response. Overall, the result of combining these agents on methaemoglobin was additive.

Animals↗
PubMed1992

Lead-induced cell proliferation and organ-specific tumorigenicity.

While lead acetate is a renal carcinogen in rodent studies, the mechanism by which it induces cancer has not been established. This report proposes that the enhanced susceptibility of renal tubular epithelial cells to lead-induced mitogenicity at the levels comparable to those administered in the cancer bioassay may contribute to the carcinogenic response seen in this target organ. Of relevance is that the nonresponsiveness of the liver to lead-induced carcinogenicity was associated with significantly less capacity (i.e., 675-fold) of lead to induce the mitogenic response in the rodent liver.

Animals↗
PubMed1992

Mink as a predictive model in toxicology.

This paper reviewed the biomedical and toxicological database concerning the use of mink as a predictive model of human responses. It is concluded that substantial information exists on the mink genetics, physiology, metabolism, nutritional requirements, and susceptibility to infectious disease; and provides a foundation upon which interspecies extrapolation may be considered. In addition, information on the response of mink to several dozen toxic substances revealed that mink respond in a qualitatively and quantitatively similar manner to other more commonly employed species as well as humans. Our conclusion does not infer that mink should be used routinely in toxicological testing for estimation of human responses. However, it indicates that toxicological data from this species may be a useful complement in risk assessment processes based upon data obtained from traditionally employed models such as rats and dogs.

Animals↗
PubMed1991

A guide to interpreting soil ingestion studies. I. Development of a model to estimate the soil ingestion detection level of soil ingestion studies.

This paper provides a model with which to predict soil ingestion recovery values in soil ingestion studies either retrospectively or prospectively. The predictive equations generated from the model can be used to estimate minimum soil ingestion detection levels from soil ingestion studies which use mass-balance methods. The model is derived from data assessing soil recovery efficiencies in adults using eight different predictive tracer elements. The results constitute a methodology for determining minimum detection levels of soil ingestion and hence have important regulatory significance.

Humans↗
PubMed1991

A guide to interpreting soil ingestion studies. II. Qualitative and quantitative evidence of soil ingestion.

Four major studies have attempted to qualitatively and quantitatively assess the extent of soil ingestion in children using the soil tracer methodology. The validity of the estimates of soil ingestion in each study was reevaluated in light of the inherent strengths and limitations of study design and/or execution, as well as via a novel methodology for estimating the soil recovery variance for each tracer, which then led to the estimation of soil ingestion detection limits for each tracer for studies performing mass-balance analyses. Based on these analyses it is concluded that the Binder et al. (1986, Arch. Environ. Health 41, 341-345) and Van Wijnen et al. (1990, Environ. Res. 51, 147-162) studies provide no convincing evidence to support qualitative and quantitative estimates of soil ingestion due to inherent limitations in their respective study designs. The Davis et al. (1990, Arch. Environ. Health 45, 112-122) and Calabrese et al. (1989, Regul. Toxicol. Pharmacol. 10, 123) studies displayed convincing qualitative evidence of soil ingestion. However, the results indicate that the median soil ingestion estimates of Davis et al. were less reliable than those of Calabrese et al. The range of detection limits vary according to the tracer and the assumption of acceptable precision in recovery estimation. The minimum detection level of soil ingestion in children in the Calabrese et al. study, with a variance in recovery of 100% +/- 20%, was 21 mg/day based on Zr.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Evidence of soil-pica behaviour and quantification of soil ingested.

A previously published report on soil ingestion in children, revealed evidence that one of the subjects, a 3.5-year-old female, displayed soil-pica behaviour. Soil ingestion estimates for this child ranged from approximately 5 to 7 g d-1 for seven of eight soil tracers employed. The present paper revealed that the soil-pica behaviour occurred only in the second of the two weeks of observation, during which daily soil ingestion rates ranged from 10 to 13 g d-1. Tracer recovery studies displayed acceptable precision (i.e. 100% less than +/- 30%) for six of the eight tracers during the soil-pica episode (week 2). Evaluation of the weekly soil ingestion values of the remaining 63 subjects indicated no convincing evidence of soil-pica behaviour in this group of children aged 1-4.

Child Behavior↗
PubMed1990

Preliminary adult soil ingestion estimates: results of a pilot study.

Six adults were evaluated for the extent to which they ingest soil. This study was originally part of a large childhood soil ingestion study and was used to validate part of the analytical methodology used in that larger study. The adult study followed the soil tracer methodology of the children's study. The principal findings of the adult study revealed that the four most reliable tracer elements based on recovery studies in a mass balance assessment [aluminum (Al), silicon (Si), yttrium (Y), and zirconium (Zr)] yielded the following mean daily adult soil ingestion estimations: Al (77 mg), Si (5 mg), Y (53 mg), and Zr (22 mg). The median daily soil ingestion estimations based on these same tracer elements were: Al (57 mg), Si (1 mg), Y (65 mg), and Zr (-4 mg). These findings represent the first published quantitative estimates of soil ingestion by adults.

Adult↗
PubMed1979

Does exposure to elevated levels of lead enhance sodium induced hypertension?

Numerous community drinking water sources have elevated levels of both sodium and lead. Recently reported studies have indicated that elevated levels of sodium in drinking water may be a facter in the development of elevated blood pressure. The question of how elevated levels of lead may affect sodium induced elevated blood pressure is addressed. The hypothesis is developed which states that elevated levels of lead exposure will not interact with sodium to enhance the development of renin angiotensin aldosterone related hypertension but in fact may even diminish the effects of exposure to elevated amounts of sodium on blood pressure through a depression of plasma renin activity.

Animals↗
PubMed1979

Conjoint use of laetrile and megadoses of ascorbic acid in cancer treatment: possible side effects.

Individuals who have a reduced capacity to detoxify cyanide to thiocyanate are at increased risk to experience adverse side effects from laetrile, a cyanide containing substance used in cancer treatment. Since megadoses of ascorbic acid may markedly diminish body stores of cysteine, a sulfur containing amino acid which facilitates the detoxification of cyanide, it is predicted that persons consuming megadoses of ascorbic acid will be at increased risk to experience the adverse side effects from laetrile treatment.

Amygdalin↗
PubMed1979

Possible adverse side effects from treatment with laetrile.

Individuals who have a diminished capacity to detoxify cyanide to thiocyanate because of either a genetic predisposition (e.g. as occurs in those with Leber's Optic Atrophy) or a diet low in sulfur containing amino acids are predicted to be at increased risk to developing adverse side effects from laetrile, a cyanide containing substance used in cancer treatment.

Amygdalin↗
PubMed1979

Is the role of the environment in carcinogenesis overestimated?

The dominant role of the physical and chemical environment in the development of cancer is challenged. Analyses of the etiology of skin, bladder, respiratory and gastric cancers are presented which demonstrate the considerable extent to which one's health status may modify the initiation and promotion of environmentally associated cancers. It is concluded that although environmental factors may initiate and/or promote 85 to 90 percent of all cancers this is misleading since it neglects the critical role of the individual's health status as a factor modifying carcinogenesis.

Ascorbic Acid↗
PubMed1979

Is the selenium drinking water standard justified?

Four cases are presented which suggest that the present U.S.E.P.A. drinking water standard for selenium of 10 micrograms/L in inappropriate. The rationale upon which this standard is based is that selenium is carcinogenic, induces dental caries formation, and is highly toxic to animals. However, a critical assessment of this literature can not support these claims. Case no. 1 demonstrates that there is insufficient evidence to classify selenium as a carcinogen. Data derived from the three respective groups of researchers claiming a carcinogenic effect induced by selenium are obscure due to 1) the inability to accurately identify malignancies, 2) the apparent opposite effects of different selenium compounds, and 3) the lack of proper controls. Case no. 2 reviews recent evidence that selenium reduces the incidence of cancer in laboratory animals and in man, an effect which can probably be attributed to the antioxidant properties of selenium compounds. Case no. 3 provides evidence which does not permit the classification of selenium as a cariogenic element. Epidemiological studies supporting such a claim are inadequate since they lack properly matched control groups. Animal data do not support this link as well. Case no. 4 is a review of studies which clearly demonstrate the essentiality of selenium, an aspect of selenium metabolism that was not considered when the 10 micrograms/L standard was promulgated. In light of the four cases presented and an assessment of selenium toxicity in man, it is concluded that the 10 micrograms/L standard can not be justified. Instead, it is suggested that 50 micrograms/L selenium should provide sufficient protection from the toxic effects of this element. This is consistent with the current state of knowledge with respect to the potential adverse health effects associated with selenium.

9,10-Dimethyl-1,2-benzanthracene↗