Lake Michigan and its Surrounding Areas: Heavy Metal Ions and the Negative Impacts

Heavy metal ion soil concentration in different regions of Lake Michigan area

Heavy metals have many negative effects on the environment, ranging from carcinogenicity to widespread microorganism death. Two of the heavy metals often focused on are lead and zinc. Because of the myriad effects and increasing prevalence of heavy metals in industry and the environment, many environmental agencies and research groups have devoted considerable time and efforts into determining the extent to which these metals are harmful.

Currently, it is agreed upon that lead causes “delayed or impaired neurobehavioral development, decreased hearing acuity, speech and language handicaps, growth retardation, poor attention span [and general] cellular damage” in all ages, particularly children.1 It also causes decreased growth and birth rates in ecosystems.2 Zinc, while considered less dangerous than lead due to the necessity for a higher concentration to cause damage, is well-known for causing decreased survival in numerous soil microorganisms.3 However, zinc is also necessary for plant growth and some human processes, provided it is in a low concentration. While the general effects of these metals on the environment and their spread via air are known, little headway has been made in determining the extent to which this influences soil concentration.

Research concerning heavy metal soil concentration is important for residential awareness, especially in rural areas where fertilizers and pesticides are common and in urban centers where pollution is high. Altogether, it aids in ensuring human safety in any region where there exists high levels of heavy metals by determining sources that spread greater concentrations of heavy metals into their surroundings.

The increasing level of heavy metals has been traced to two major factors: pollution and agricultural aids.4 In many industries, lead and zinc are released into the air during production as waste. In addition, vehicles release lead and zinc as soot. Fertilizers often contain large amounts of steel industry waste due to its high concentration of zinc, which also contains levels of lead and other carcinogenic heavy metals.

In order to determine the extent of the spread of zinc and lead from different sources, three locations were chosen for soil testing: Gensberg-Markham Prairie, a nature reserve in Illinois near two major highways, Chicago and its industry; Pleasant Prairie, a wooded area surrounded by corn fields in rural Wisconsin; and Benton Harbor, a wooded area in Michigan near a medium-traffic road. Because of its proximity to two major highways, Chicago, and steel refineries, Gensberg-Markham Prairie is expected to the highest lead and zinc content of the three sites, followed by Pleasant Prairie, which is surrounded by corn fields and potentially heavy metal-rich fertilizers and pesticides; Benton Harbor, close to a medium-traffic road, is expected to have the lowest concentration of lead and zinc because of its lack of heavy metal polluters.

The measurement of lead and zinc levels of the three regions will aid in determining to what extent vehicle emissions, industry, and agricultural aids release heavy metals into the surrounding areas, taking into account each sample’s distance from the nearby polluting system as well as the polluting system itself. This will enable environmental protection agencies to determine the safety of each region and potentially lead to legislation reforming heavy metal pollution near residential areas.