Elements of Environmental Risk Assessment Case Study Evaluation April’s Part: (please omit)

Elements of Environmental Risk Assessment Case Study Evaluation

April’s Part: (please omit)

The case study on the risk assessment of chromium-contaminated soils illustrates how

our understanding of attainable health risks can improve with the combination of scientific data

from directed research into risk assessment. It presents the case study of a group of hazardous

waste sites in northern New Jersey, where a chain of non-tradition research efforts were

implemented over the past 12 years so that the accuracy of the risk assessment process can be

improved. This case study reports how applied science is used to advance the characterization of

both toxicity and exposure associated with hexavalent and trivalent chromium [CR (III) and CT

(VI)] being uncontrollably released in an urban setting, while in the chromites ore processing

residue (COPR) form. The case study’s ultimate goal was to gather all of the information that is

needed to identify the remedial goals that are health-based (such as soil cleanup standards) using

only the best science available. It also described how research was focused on locating and

filling data gaps to clearly address and later replace default or conservative assumptions

pertaining to health risks and exposure identified, along with the site-specific and refined

information by the New Jersey Department of Environmental Protection (NJDEP).

Early investigations started when Jersey City was being rebuilt into an upgraded

community of New York City. While some of the areas were being redeveloped, there were

developments of COPR being found. In 1983, a researcher named Earl Tex Aldredge, who

considered himself to be the “Toxic Avenger” of the city’s hazardous waste task force, identified

COPR on a development site that was constructing townhouses (Stapinski, 1993). Later research

performed by the NJDEP and the task force revealed that hauling firms and construction

companies had been using and selling COPR as bases for buildings and parking lots, to fill the

Elements of Environmental Risk Assessment
Case Study Evaluation

basements of demolished buildings, and for filling low-lying areas. The information that the

NJDEP gained from this investigation is that two million tons of COPR that contained anywhere

from two to five percent of chromium, was produced by three chromate plants.

After the investigation from COPR was conducted, the resulting uncertainties started

with the analytical method that was used to analyze ACR (VI). There were no regulator-

approved method that was used to extract CR (VI) from solid samples at the time of the remedial

investigation and this caused the findings to be biased and overestimated. As a conclusion to the

investigations conducted for COPR in the late 1980s, there were a considerably amount of

uncertainty on how to better characterize the COPR site’s potential health risks. The NJDEP

suggested that the sites could likely cause serious hazards. It also concluded that COPR must be

removed to the safe background concentration of 100 mg/kg of the total chromium (Paustenbach,

2002).

A human health risk assessment involves the process that estimates the probability and

nature of the adverse health effects in humans that are exposed to chemicals that are in

contaminated areas now and in the future. The four steps of human risk assessment are: (1)

hazard identification, (2) dose-response assessment, (3) exposure assessment, and (4) risk

characterization. The first step, hazard identification, examines whether or not a stressor has the

potential to harm humans or the environment and is proven to cause harm. Hazard identification

is not the answer when making a risk management decision, but it is an important step that is

carried out often before products and chemicals are introduced on the market. For human health,

the results from epidemiology as well as toxicity testing were used to determine the hazard.

Dose-response assessment is the second step in human health risk assessment, and it

examines all of the numerical relationships that takes place between exposure and effects. It is

Elements of Environmental Risk Assessment
Case Study Evaluation

the determination of the relationship between the degree of an applied, internal, or administered

dose, and a particular biological response. A dose-response assessment describes the

extrapolation methods used to predict an incidence, and should identify the biologic and

statistical uncertain ties used with these methods (Paustenbach, 2002). Exposure assessment is

the third step in human health assessment, and it examines what is known about the timing,

frequency, and degree of contact with stressors. Exposure assessment is often used in predicting

effects of control techniques that are available for limiting or controlling agent exposure.

The fourth and final step in human health risk assessment is risk characterization. Risk

characterization examines just how well the gathered data support conclusions based on the

extent and nature of a risk from exposure to environmental stressors. It summarizes data from

hazard identification, dose-response assessment, and exposure assessment into a conclusion on

the risk. An estimation of the short term damage to humans from the exposure to COPR can

range from skin irritation to ulcerations. With long-term exposure, damage to the liver, nerve

tissues, and kidney failure could occur.

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