Patricia L. Toccalino

Calculated Cancer Risks for Conventional and “Potentially Reduced Exposure Product” Cigarettes

Toxicant deliveries (by machine smoking) are compiled and associated cancer risks are calculated for 13 carcinogens from 26 brands of conventional cigarettes categorized as “regular” (R), “light” (Lt), or “ultralight” (ULt), and for a reference cigarette. Eight “potentially reduced exposure product” (PREP) cigarettes are also considered. Because agency-to-agency differences exist in the cancer slope factor (CSF) values adopted for some carcinogens, two CSF sets were used in the calculations: set I [U.S. Environmental Protection Agency (EPA)–accepted values plus California EPA–accepted values as needed to fill data gaps] and set II (vice versa). The potential effects of human smoking patterns on cigarette deliveries are considered. Acetaldehyde, 1,3-butadiene, and acrylonitrile are associated with the largest calculated cancer risks for all 26 brands of conventional cigarettes. The calculated risks are proportional to the smoking dose z (pack-years). Using CSF set I and z = 1 pack-year (7,300 cigarettes), the calculated brand-average incremental lifetime cancer risk \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\overline{\mathrm{ILCR}}^{\mathrm{acetaldehyde}}_{1}\) \end{document} values are R, 6 × 10−5; Lt, 5 × 10−5; and ULt, 3 × 10−5 (cf. typical U.S. EPA risk benchmark of 10−6). These values are similar, especially given the tendency of smokers to “compensate” when smoking Lt and ULt cigarettes. \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\overline{\mathrm{ILCR}}^{\mathrm{sub{\Sigma}-lung}}_{1}\) \end{document}is the brand-average per pack-year subtotal risk for the measured human lung carcinogens. Using CSF set I, the \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\overline{\mathrm{ILCR}}^{\mathrm{sub{\Sigma}-lung}}_{1}\) \end{document} values for R, Lt, and ULt cigarettes account for ≤2% of epidemiologically observed values of the all-smoker population average per pack-year risk of lung cancer from conventional cigarettes. RPREP (%) is a science-based estimate of the possible reduction in lung cancer risk provided by a particular PREP as compared with conventional cigarettes. Using CSF set I, all RPREP values are <2%. The current inability to account for the observed health risks of smoking based on existing data indicates that current expressed/implied marketing promises of reduced harm from PREPs are unverified: there is little reason to be confident that total removal of the currently measured human lung carcinogens would reduce the incidence of lung cancer among smokers by any noticeable amount. (Cancer Epidemiol Biomarkers Prev 2007;16(3):584–92)

Methods and Sources of Data Used to Develop Selected Water-Quality Indicators for Streams and Ground Water for the 2007 Edition of The State of the Nation's Ecosystems Report with Comparisons to the 2002 Edition

The U.S. Geological Survey (USGS) was one of numerous governmental, private, and academic entities that provided input to the report The State of the Nation’s Ecosystems published periodically by the Heinz Center. This report describes the sources of data and methods used by the USGS to develop selected water-quality indicators for the 2007 edition of the Heinz Center report and documents modifications in the data sources and interpretations between the 2002 and 2007 editions of the Heinz Center report. Stream and ground-water quality data collected nationally as part of the USGS National Water-Quality Assessment Program were used to develop the ecosystem indicators for the Heinz Center report, including Core National indicators for the Movement of Nitrogen and Chemical Contamination and for selected ecosystems classified as Farmlands, Forest, Grasslands and Shrublands, Freshwater, and Urban and Suburban. In addition, the USGS provided water-quality and streamflow data collected as part of the National Stream Water Quality Accounting Network and the Federal–State Cooperative Program. The documentation provided herein serves not only as a reference for current and future editions of The State of the Nation’s Ecosystems but also provides critical information for future assessments of changes in contaminant occurrence in streams and ground water of the United States.