Tracy Punshon

Publications (29) View all

• Article: Element levels in snakes in South Carolina: differences between a control site and exposed site on the Savannah River site.

  J Burger, S Murray, K F Gaines, J M Novak, T Punshon, C Dixon, M Gochfeld
  [show abstract] [hide abstract]
  ABSTRACT: Levels of 18 elements, including lead, mercury, selenium, and uranium, were examined in three species of snakes from an exposed and reference site on the Department of Energy's Savannah River Site in South Carolina. We tested the hypotheses that there were no differences as a function of species, and there were no difference between the exposed and control site for blood and muscle (tail) samples for banded water snake (Nerodia fasciata), brown water snake (N. taxispilota) and cotton mouth (Akistrodon piscivorous). The banded water snakes collected were significantly smaller than the other two species. For blood, there were significant species differences only for barium, copper, selenium, uranium and zinc, while for muscle tissue there were significant interspecific differences in aluminum, arsenic, barium, cobalt, cesium, copper, iron, lead, mercury, manganese, strontium, vanadium and zinc, suggesting that muscle tissue in the tail is a better indicator of potential interspecific differences. It is also easier logistically to collect tail tissue than blood. Where one species had significantly higher levels than the other species in muscle tissue levels, cottonmouth had higher levels of five elements (aluminum, cobalt, lead, mercury, vanadium), brown water snake had two (lead, strontium), and banded water snake had only barium. There were few significant differences between the control and reference site for levels of blood, but several for muscle tissue. All three species had significantly higher levels of arsenic and manganese at Tim's Branch than the reference site, and nickel and uranium were significantly higher for banded water snake and cotton mouth, the larger species. Individuals with high exposure of one element were exposed to high levels of other elements.
  Environmental Monitoring and Assessment 02/2006; 112(1-3):35-52. · 1.40 Impact Factor
• Chapter: Production of Coal Combustion Products and Their Potential Uses

  K. S. Sajwan, T. Punshon, J. C. Seaman
  [show abstract] [hide abstract]
  ABSTRACT: Coal Combustion Products (CCPs) arise from the combustion of coal for energy, with fly ash (FA), bottom ash (BA) and flue-gas desulfurization residues (FGD) the most abundant. Our reliance on fossil fuel for energy is set to continue into the 21st century, and research into the environmental safety of beneficial re-use options, as well as novel re-use options, must continue. Since previous editions of collected CCP research1, significant changes have been made to both the New Source Review and the Clean Air Act that directly impact CCP production figures. New techniques such as x-ray absorption spectroscopy are increasingly being used to reveal micron-scale elemental characteristics of CCPs, and aid our understanding of the distribution and chemical form of the metallic constituents. This chapter summarizes production and use covering the period 2001–2003, new trends in reuse applications and discusses new research on the environmental safety of CCP re-use.
  12/2005: pages 3-9;
• Article: Rice consumption and urinary arsenic concentrations in u.s. Children.

  Matthew A Davis, Todd A Mackenzie, Kathryn L Cottingham, Diane Gilbert-Diamond, Tracy Punshon, Margaret R Karagas
  [show abstract] [hide abstract]
  ABSTRACT: Background: In adult populations, emerging evidence indicates that humans are exposed to arsenic by ingestion of contaminated foods such as rice, grains, and juice; yet little is known about arsenic exposure among children.Objectives: Our goal was to determine whether rice consumption contributes to arsenic exposure in U.S. children.Methods: We used data from the nationally representative National Health and Nutrition Examination Survey (NHANES) to examine the relationship between rice consumption (measured in 0.25 cups of cooked rice per day) over a 24-hr period and subsequent urinary arsenic concentration among the 2,323 children (6-17 years of age) who participated in NHANES from 2003 to 2008. We examined total urinary arsenic (excluding arsenobetaine and arsenocholine) and dimethylarsinic acid (DMA) concentrations overall and by age group: 6-11 years and 12-17 years.Results: The median [interquartile range (IQR)] total urinary arsenic concentration among children who reported consuming rice was 8.9 μg/L (IQR: 5.3-15.6) compared with 5.5 μg/L (IQR: 3.1-8.4) among those who did not consume rice. After adjusting for potentially confounding factors, and restricting the study to participants who did not consume seafood in the preceding 24 hr, total urinary arsenic concentration increased 14.2% (95% confidence interval: 11.3, 17.1%) with each 0.25 cup increase in cooked rice consumption.Conclusions: Our study suggests that rice consumption is a potential source of arsenic exposure in U.S. children.
  Environmental Health Perspectives 07/2012; 120(10):1418-24. · 7.04 Impact Factor
• Article: Erratum to: A review of recent developments in the speciation and location of arsenic and selenium in rice grain.

  Anne-Marie Carey, Enzo Lombi, Erica Donner, Martin D de Jonge, Tracy Punshon, Brian P Jackson, Mary Lou Guerinot, Adam H Price, Andrew A Meharg
  Analytical and Bioanalytical Chemistry 02/2012; 402(10):3379. · 3.78 Impact Factor
• Article: Arsenic concentration and speciation in infant formulas and first foods.

  Brian P Jackson, Vivien F Taylor, Tracy Punshon, Kathryn L Cottingham
  [show abstract] [hide abstract]
  ABSTRACT: Arsenic exposure to humans is pervasive, and, increasingly, studies are revealing adverse health effects at ever lower doses. Drinking water is the main route of exposure for many individuals; however, food can be a significant source of arsenic to an individual, especially if their diet is rice-based. Infants are particularly susceptible to dietary exposure, since many first foods contain rice and they have a low body mass. Here we report on arsenic concentration and speciation in infant formulas and first foods. Speciation is essential for food analysis because of the much greater toxicity of inorganic arsenic species and the possibility that arsenic in food (unlike water) may be present in either inorganic or organic forms. Infant milk formulas were low in total arsenic (2.2-12.6 ng g(-1), n=15). Non-dairy formulas were significantly higher in arsenic than dairy-based formulas. Arsenic in formula was almost exclusively inorganic and predominantly arsenic(V). Arsenic concentration in purees (n=41) and stage 3 foods (n=18) ranged from 0.3-22 ng g(-1). Rice-fortified foods had significantly higher total arsenic concentrations than non rice-based foods. Again arsenic speciation was predominantly inorganic; arsenic(III) was the main species with lower concentrations of DMA and arsenic(V) also present. These data confirm that infants are exposed to arsenic via diet, and suggest that careful attention to diet choices may limit this.
  Pure and Applied Chemistry 01/2012; 84(2):215-223. · 2.79 Impact Factor