Statistical Procedures in the New

¶ … Statistical Procedures

In the New York Times article "Child Obesity is Linked to Chemicals in Plastics" (April 17, 2009), Jennifer B. Lee discusses how exposure to certain chemicals currently found in many plastic products has been linked to childhood obesity. Her basic argument is founded upon a long-term health study conducted by the Mount Sinai Medical Center in East Harlem, New York, which examined a large group of girls who reside in East Harlem that suffer from childhood obesity. The alleged culprit are chemicals known as phthalates which are used to manufacture pliable plastic products and have been shown to affect the endocrine system which regulates a number of bodily functions, thus creating obesity in children who use these products (2009, Internet).

As to the types of research procedures utilized in this study, the Mount Sinai Medical Center via its "Growing Up Healthy in East Harlem" research project, utilized a sampling group of "more than three hundred children in East Harlem and an additional two hundred" from surrounding communities. Of this group, 40% were considered as overweight or obese, most of which were kindergarten children (Lee, 2009, Internet). This sampling group was apparently preceded by an earlier control group, made up of four hundred girls ranging in age from nine to eleven who had experienced weight problems similar in nature to the later group.

In addition, Lee points out that because of the findings gathered from these two surveys, the National Children's Study will be conducted in the near future which will "follow 100,000 children from across the country from birth to age twenty-one," in a search for conclusive evidence related to the medical link between phthalates and childhood obesity (2009, Internet). One important aspect which Lee has failed to include in her article is what types of experiments were conducted by the researchers in order to determine the levels of phthalates, with the exception of using a simple urine test.

Unfortunately, Lee does not provide any indication in this article pertaining to the statistical procedures applied by the survey study. However, it is clear that the researchers did utilize what is known as a one-way ANOVA (analysis of variance) via a general survey model, being the two groups of children, i.e., the first group of five hundred and the second group of four hundred. Technically speaking, this one-way ANOVA is utilized by researchers "to test for variances and differences among two or more independent groups" (Famoye & Lee, 2009, Internet).

For example, with the first group of five hundred children, the researchers determined that the girls that were most obese or heaviest had the "highest levels of phthalates metabolites in their urine" (Lee, 2009, Internet) as compared to girls in the study sample who were not significantly overweight. Thus, the researchers concluded that environmental factors were part of the overall equation, determined by comparing the amount of phthalates in those girls who live close to urban areas with factories that manufacture products containing phthalates. One other finding drawn from this sample group was that the levels of phthalates "were significantly higher than the average levels" determined by the CDC (Lee, 2009, Internet).

With the second group of four hundred, the researchers produced similar findings, even though this group preceded the first by some ten years, an indication that phthalates have been in the environment for at least this length of time. Also, via utilizing the one-way ANOVA model, the researchers discovered a correlation between phthalates and IQ which was lower in those girls with heavy exposure to the chemical. However, the researchers admit that this possible link may be simply "cause and effect or an accidental finding" (Lee, 2009, Internet). Nonetheless, both of these studies on the first and second groups of girls clearly indicates the frequency of phthalates, for it was discovered in the urine of both sampling groups despite being separated by ten years.

Presumably, the researchers that participate in the up-coming National Children's Study will also utilize the one-way ANOVA model in order to "look more broadly at endocrine disruptors" (Lee, 2009, Internet) which have been shown to contribute to being overweight and/or obese. Once this is completed, the researchers will then presumably utilize some form of linear regression which is used to analyze variables in order to create a model based on the data and findings in the shape of a mathematical equation.