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C F Chaisson

Publications and source records attributed to C F Chaisson.

7 recordsLinked to original sources
PubMed2001

Assessing aggregate and cumulative pesticide risks using a probabilistic model.

Determining aggregate and cumulative risks from exposures to pesticides presents a number of challenges. The analysis must capture the correlations in residues that occur from both additive and exclusionary processes in the use of pesticides. The analysis also requires a quantitative mechanism for evaluating risks associated with exposures to mixtures of pesticides. This paper presents an analysis of aggregate exposures and risks associated with exposures to a pesticide, Alpha, and the cumulative exposure to and risk from three pesticides, Alpha, Beta, and Gamma. The cumulative risks are evaluated by determining the systemic (absorbed) doses that result from inhalation, dermal, and oral exposures to the pesticides. A 'relative toxicity' model is used to evaluate cumulative risks. The assessment of cumulative exposure was performed using the LifeLine Version 1.0. The model simulates pesticide exposure using an individual-based approach where daily exposures are evaluated for each person, season, and location.

Administration, Cutaneous↗
PubMed1994

Use of food-intake surveys to estimate exposures to nonnutrients.

Several steps must be taken in estimating intake of (or exposure to) dietary nonnutrients such as additives, drug residues, pesticide residues, toxicants, and natural nontoxicant chemicals. The first step involves consideration of relevant characteristics of the nonnutrient, including biological activity, physical/geographical sources, distribution in the food supply, typical concentrations, and the desirability of intake. After reviewing chemical characteristics, appropriate food-consumption data to use in the exposure assessment must be identified and obtained. Survey methodology must be reviewed carefully to determine compatibility with the characteristics of the chemical. The best available nonnutrient concentration data must be identified and obtained and the exposure models must be chosen. Available models include average exposure, simple distribution, joint distribution, and commodity contribution.

Adolescent↗
PubMed1978

2-Deoxy-D-glucose uptake by lung slices from fed and fasted rats.

We studied the uptake and phosphorylation of 2-deoxy-D-[1-14C]glucose (2-[14C]DG) by lung slices from fed and fasted rats to obtain information on the effect of starvation on surgar transport by the lung. We found that 2-[14C]DG is taken up and phosphorylated by the lung, but that, as in other tissues it is not metabolized beyond the phosphorylation step. The accumulation of 2-[14C]DG as free 2-DG does not require energy, fails to show saturation in the range studied (5-100 mM), and is not inhibited by exogenous glucose. The phosphorylation of 2-DG by the lung is energy dependent, saturable, and competitively inhibited by exogenous glucose. Fasting does not interfere with the intracellular accumulation of unphosphorylated 2-DG but causes about a 40% decrease in the accumulation of phosphorylated 2-DG. We conclude that membrane transport does not limit uptake of 2-DG; fasting decreases the phosphorylation of 2-DG.

Animals↗
PubMedDate not supplied

Harmonization of strategies for utilizing available data on a pan-European basis.

Harmonization must proceed for setting the objectives and priorities, for the technical understanding and utilization of data and information, and for the application of the information to regulatory strategies. At the moment there is disharmony along these three lines but there exists great advantage and opportunity in the pan-European situation. There is a wealth of different kinds of data, information tools, models and experience. There is a willingness for open discussion of the sciences, costs and responsibilities. No historical mould inhibits the process. To maximize the opportunities for success, the European Union--government and industry--should collect and use available data for dietary intake assessments then evaluate the utility of the data and models. An independent working group should develop criteria for application of the data and for development of new data. A secure clearing-house should be established to facilitate equitable use of private and public databases.

Diet↗
PubMedDate not supplied

Evaluation of the budget method for screening food additive intakes.

The Budget Method, originally developed for determining food additive use limits, has been proposed as a tool for screening food additive intakes to establish monitoring priorities. Theoretical Maximum Daily Intake (TMDI) estimates derived using the Budget Method rely on assumptions regarding physiological requirements for energy and liquid and on the energy density of food rather than on food consumption survey data. This report summarizes work performed to determine the validity of Budget Method assumptions and to assess the potential for error in assigning monitoring priority based on Budget Method results. Budget Method assumptions regarding energy and liquid intake were compared with data from UK, German and US nationwide food consumption surveys. It was found that the Budget Method assumptions of energy intake and liquid intake are higher than mean intakes reported in surveys. The Budget Method assumption regarding energy density of foods also was found to be a slight overestimate. Budget Method TMDIs for case study additives were in each case larger than survey-based 95th percentile per capita additive intake estimates. Based on these results, the Budget Method appears to be a suitably conservative screen for establishing additive monitoring priorities based on potential lifetime average intakes.

Beverages↗