For Professor Goodman Only

Unit III Article Critique

You are to choose an article that covers a topic presented in this unit. The article itself must be more than one page in length. Some suggested topics include: Environmental case studies, environmental toxicology, environmental chemistry, environmental exposure to pollutants, persistent chemicals in the environment, environment and toxicology, or pollution and health effects. The assignment must include the following components: 1. a brief introduction to the article, 2. a summary and analysis of the key points of the article, 3. a decision on whether or not the article supports the concepts as presented in the textbook. 4. a summary of the article’s conclusions and your own opinions. The assignment must be a minimum of two pages but no more than four pages in length, double-spaced, and in APA style. Ensure you use APA references and in-text citations in your critique.

Different pollutants show same impact Full Text:

At concentrations present in the environment, each of three dissimilar toxic agents can seize control of a signaling pathway that regulates developing cells in the brain and spinal cord, researchers report. They suggest that scientists might use the pathway to predict the toxicology of a diverse range of chemicals.

Mark Noble of the University" of Rochester Medical Center in New York and his colleagues focused on a pathway that controls the development of cells destined to become oligodendrocytes. Those mature cells produce the material that insulates nerve fibers.

Despite vast differences in structure, many toxic agents in the environment can oxidize cells, notes Noble. In normal development, subtle changes in the oxidative state of the oligodendrocyte precursors determine whether they continue to divide or proceed to their final form. To study how oxidizing chemicals would affect this development, the group exposed cultures of the progenitor cells from newborn rats to methylmercury, lead, and the herbicide paraquat. The researchers applied the chemicals in amounts that people or animals encounter in the environment.

Each chemical slightly shifted the oxidative state of the progenitor cells, in effect telling the cells to mature. That action halted division in 25 percent of the cells. This decrease, Noble says, when carried through many cellular generations, "has an enormous effect on the number of cells that you have."

The researchers also investigated the effect of one of the chemicals in animals. They provided pregnant mice with drinking water that contained environmentally relevant concentrations of methylmercury. The brains of the pups from those mothers had 20 percent fewer oligodendrocyte progenitor cells than did brains from pups of untreated mothers, the team reports in the February PLoS Biology.

Noble's group plans longer studies to determine the consequences of a decreased pool of oligodendrocyte progenitor cells.

By identifying a pathway that might be vulnerable to different environmental chemicals, the research "provides a framework for predictive toxicology" comments David A. Schwartz, director of the National Institute of Environmental Health Sciences in Research Triangle Park, N.C., which partially funded the study. Because exposure to lead gave a similar biological fingerprint as the exposure to methylmercury did, he says "perhaps it predicts what the fingerprint might be for an exposure to arsenic" which also oxidizes cells.

"It's a little too early to tell how generalizable [the finding] will be," Schwartz continues, but if it proves to hold true for other toxic agents, it could affect "not only how we measure the effects of toxicants, but how we predict risk of disease."

Joel G. Pounds, a toxicologist at the Pacific Northwest National Laboratory in Richland, Wash., agrees. If the pathway is a target for many toxic agents, he says, then by finding ways to measure the pathways activity, "we can begin to use those probes to understand the relationship between exposure to the toxicant and the role of the toxicant in chemically induced disease."

Cunningham, A.

Source Citation (MLA 7th Edition) Cunningham, A. "Different pollutants show same impact." Science News 3 Mar. 2007: 134. General OneFile. Web. 24 May 2015. URL http://go.galegroup.com/ps/i.do?id=GALE%7CA160812412&v=2.1&u=oran95108&it=r&p=IT OF&sw=w&asid=c4c90e7c3cb2ab998aa9a168b1d6214a