Spatial analysis is a very powerful tool for policy makers to utilize in helping to make decisions when major decisions need to be made regarding controversial subjects such as building or expanding landfills and its effect on the health of those living near the areas in question. GIS helps to manage and analyze data of the various factors affecting the decision. Spatial analysis of the suitability of an area of land to build a landfill on is especially complicated as it may involve slope analysis, distance to bodies of water, land cover, soil drainage, and distance to other landfills. Thus, using GIS to help inform policy makers about the suitability of building landfills on certain plots of land will be important.
A toxic waste landfill in Kettleman City, California, has been planning to expand its capacity to take in more . However, residents of Kettleman City have reported increased rates of birth defects and blamed the landfill for this increase. Senators and the EPA have gotten involved with the investigation due to the outcry of the residents regarding the death of infants who suffered from birth defects and have suspended the expansion of the landfill pending further investigation of the health risks associated with the landfill. The owners of the landfill were surprised to hear about the suspension but were cooperative with the investigation.
A preliminary report concluded that birth defects occurring in the area surrounding the landfill were comparable to nearby communities and there were no common factors between birth defect cases . The report did not sit well with advocacy groups and residents who complained that the study was conducted haphazardly and did not include other factors that may contribute to birth defects.
It is difficult to comment on the report without knowing the specific details on the analysis that was conducted. However, in general situations when rare cases are involved it will be difficult to find associations with any factor due to the lack of statistical power. With only four cases to work with it is not surprising that the report did not find any meaningful associations between environmental factors with birth defects. Historical analysis of past rates of birth defects will need to be conducted so more cases can be involved and statistical power can be increased.
GIS also can play a major role in the investigation of the landfill and other environmental contaminants’ effect of the development of birth defects. Spatial analysis can be run on the slope, soil drain, nearby water sources, and land cover to determine which areas would be the most affected by toxic waste leakage. Wells can be plotted and see if they draw water from contaminated water sources. Pesticide use maps reported by farmers can be used to determine ambient exposure to agriculturally applied pesticides. These are just a few spatial analyses that can be conducted with GIS which can be combined to provide a more complete assessment of the factors that contribute to birth defects.
So in conclusion, I would agree with the advocacy groups and residents that the preliminary report is inadequate to determine whether or not living near the landfill are associated with birth defects.
No comments:
Post a Comment