A quantitative screening-level approach to incorporate chemical exposure and risk into alternative assessment evaluations.

As the general public and retailers ask for disclosure of chemical ingredients in the marketplace, a number of hazard screening tools were developed to evaluate the so-called "greenness" of individual chemical ingredients and/or formulations. The majority of these tools focus only on hazard, often using chemical lists, ignoring the other part of the risk equation: exposure. Using a hazard-only focus can result in regrettable substitutions, changing 1 chemical ingredient for another that turns out to be more hazardous or shifts the toxicity burden to others.

Evaluation of potential human health effects associated with the agricultural uses of 1,3-D: Spatial and temporal stochastic risk analysis.

Dow AgroSciences (DAS) markets and sells 1,3-Dichloropropene (1,3-D), the active ingredient in Telone®, which is used as a pre-plant soil fumigant nematicide in economically important crops in California. 1,3-D has been regulated as a "probable human carcinogen" and the California Department of Pesticide Regulation limits use of 1,3-D based on human health risk assessments for bystanders. This paper presents a risk characterization for bystanders based on advances in the assessment of both exposure and hazard.

Modeling duration of time lived in a residence, a community and mobility in rural areas of Merced and Ventura, California to assess potential health risks to airborne contaminants.

A de novo population mobility survey of 800 households (random digit dialing-based phone interviews) was conducted in high demand areas of the agricultural fumigant, 1,3-dichloropropene (1,3-D) in Merced and Ventura counties of California. The survey included approximately 20 questions relating to the length of time individuals had lived in the high demand areas in each county, and also relating to weekly and annual mobility patterns. Lifetime inhalation exposures to 1,3-D are determined, in part, by the number of years individuals spend in an area where the fumigant is used.

Gender differences in the incidence of background and chemically induced primary pulmonary neoplasms in B6C3F1 mice: a retrospective analysis of the National Toxicology Program (NTP) carcinogenicity bioassays.

The National Toxicology Program (NTP) database of technical reports on carcinogenicity bioassays has been interrogated for the incidence of primary pulmonary neoplasms in B6C3F1 mice. A total of 170 study reports were selected, from studies that completed the in-life phase during 1983-2007, which included neoplasm incidence data for 180 control groups comprising both male and female mice. The incidence (median and inter-quartile range) of males with alveolar/bronchiolar adenoma was 16% (12-20%), and for females it was 5% (2-8%); the incidence of males with alveolar/bronchiolar carcinoma was 8% (4-12%), and for females it was 2% (0-4%); and the incidence of males with combined alveolar/bronchiolar adenoma or carcinoma was 24% (18-30%), and for females it was 8% (6-12%).

Derivation of single layer clothing penetration factors from the pesticide handlers exposure database.

Quantitative characterization of the penetration of chemical residues through various types and configurations of clothing is an important underpinning of mitigation strategies to reduce dermal exposure to occupational cohorts. The objective of the evaluation presented herein is the development of pesticide clothing penetration (or conversely protection) factors for single layer clothing (i.e.

Recommended relative potency factors for 2,3,4,7,8-pentachlorodibenzofuran: the impact of different dose metrics.

The recent National Toxicology Program (NTP) cancer bioassays for 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and 2,3,4,7,8-pentachlorodibenzofuran (4-PeCDF) permit a reevaluation of the current TEF value of 4-PeCDF. The data also allow for the derivation of relative potency factors (RPFs) for cancer, which are based not only on administered dose but also on potentially more informative dose metrics, such as liver concentration, area under the liver concentration curve, and lifetime average body burden. Our analyses of these data indicate that chi-squared tests of observed versus predicted liver tumor incidence for 4-PeCDF reject the current TEF value of 0.

Background concentrations of dioxins, furans, and PCBs in Sprague-Dawley rats and juvenile swine.

In preparation for a study of the relative oral bioavailability of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in soils (typically containing less than 1 ppb 2,3,7,8-tetrachlo-rodibenzo-p-dioxin [TCDD] toxic equivalents [TEQ]), the background concentrations of PCDD/Fs and selected polychlorinated biphenyls (PCBs) were measured in liver and adipose tissue from female Sprague-Dawley rats and juvenile swine after 30 d of ingesting laboratory chow. The measured concentrations of TCDD and other PCDD/Fs in rat livers were severalfold less than previously reported in the literature for control (unexposed) laboratory rodents. The concentrations of PCDD/Fs and selected PCBs in livers of swine were three- to fourfold lower than those reported for rats.