Soil Pollution From Recycling Centers: Case Study Analysis from the Campus of Michigan State University
Soil composition greatly affects the health of the entire ecosystem, making it useful to investigate how anthropogenic processes impact soil chemistry. Industrial facilities are common sources of known soil contaminants. In this study, we hypothesized that the Michigan State University recycling center would alter the soil composition of the surrounding area. Soil samples were taken at various distances from the center’s dropboxes, including those from the adjacent Baker Woodlot. Analysis of the samples for aluminum, phosphorus, pH, nitrate, nitrite, ammonia, and ferric iron revealed a number of correlations with distance from the dropboxes. Phosphorus (r=-.916), ferric iron (r=-.379), aluminum (r=-.814), and pH (r=-0.658) were negatively correlated with distance. Conversely, nitrate was positively correlated (r=.766). Our results indicate that the recycling center has influenced the proximate soil. These data suggest a need to maintain strict recycling procedures that minimize negative environmental impacts.
Soil quality interacts with air and water quality to have major implications for the entire ecosystem; it affects microbial populations living in the soil, plants sprouting from the soil, and animals that are in various ways being sustained by the plants (Doran, 2000). Rousk et al. (2010) provided evidence that the abundance and diversity of bacteria are positively correlated with soil pH, to the extent that bacteria diversity actually doubled between pH 4 and 8. This is just one example of why there is an increasing interest in identifying soil quality indicators as a means of monitoring ecosystem health (Doran, 2000). Soil chemistry provides some of those indicators, so studies that analyze how anthropogenic practices affect soil chemistry will be useful ecological resources with extensive implications in the maintenance of healthy ecosystems.
A recycling center—being an industrial facility that likely increases traffic in the area—may have an effect on local soil chemistry. Recycling is now a conventional process in the United States because it has so many realized benefits. Recycling gained appreciable popularity in the 1970s with the prevalent maxim, “Save the Environment!” (“History of Recycling”). Recycling reduces the necessity of landfills, which are unpleasantly aromatic and potentially harmful because of the methane and carbon dioxide gases that emanate from them (“Landfill Gas”). Recycling also saves energy, lessens the output of greenhouse gases, reduces pollution that would be created with the manufacturing of new products, and creates a significant number of jobs (“Recycling”). We intend to investigate whether a recycling facility affects the health of the surrounding ecosystem by analyzing local soil chemistry.
Michigan State University’s new recycling facility is the archetype of these benefits in action. It has been honored with gold LEED (Leadership in Energy and Environmental Design) certification, which is the second highest level available in the United States. Having opened in 2009, this center now collects and ships out thousands of pounds of recycled material daily. It is equipped with a number of energy-saving features, including an energy recovery ventilation system, large ceiling fans to reduce heat expenses, water efficient toilets to conserve rainwater, and photovoltaic panels on the roof to contribute to the building’s required energy input. The building even uses paints and carpets that are low in VOCs (volatile organic compounds) (“MSU Surplus Store & Recycling Center”). These features are evidence to the fact that technological advances have allowed for the progression toward a greener existence.
However, despite these and countless other environmental benefits, it is possible that the recycling center itself is having a negative effect on the surrounding ecosystem; this question has not been given considerable attention in the past. Then again, a number of studies have been dedicated to examining the negative impacts of other industrial facilities on the environment; Papastergios Filippidis, Fernandez-Turiel, Gimeno, & Sikalidis (2010) ran analyses in the industrial area of Kavala, Greece to determine whether anthropogenic processes had affected the soil geochemistry there. They found that three out of the ten major elements, and five out of the 32 trace elements for which they tested were present in soil at levels that could not be explained by natural processes alone, such as the weathering of parent rocks, and therefore must be attributed to anthropogenic activities. Since the recycling center is an industrial facility, it too may have a similar impact on the surrounding ecosystem.
One important consequence to consider is whether the center alters the nitrogen content of the proximate soil, which can greatly impact the ecosystem. As a part of the nitrogen cycle, atmospheric deposition is responsible for most of the nitrogen that is introduced into an ecosystem, but the public often greatly augment this input with other factors such as fertilizer, human waste, and other pollutants (Mitchell, 2011). Stevenson et al. (2010) showed that as the anthropogenic uses of land increase so do the processes that remove nitrogen from an ecosystem, such as nitrification, nitrate leaching, and ammonia volatilization. This, in turn, will increase the total nitrogen levels in the soil. Nitrogen—found in the form of nitrate, nitrite and ammonia—is often the limiting factor in regard to plant growth (Vitousek et al., 1979); elevated levels of these can stimulate primary production to an extent, but can also have detrimental effects on the water quality in the area (Mitchell, 2011). In addition, another study conducted by Boto (1983) demonstrated that the amount of phosphorus and ammonium present in the soil correlated with mangrove production in northwestern Australia. This research suggests that, like nitrogen content, phosphorus and ammonium content are integral factors affecting plant growth.
Besides the direct impact of the industrial center, there is also a plethora of evidence for a relationship between vehicle emissions and increased pollution. Spencer (1988) found that fewer plants grew within six meters of the roadway than grew at a distance greater than six meters. The soil by the road absorbed nitrogen such that plants, when deliberately grown in roadside soil, had significantly higher nitrogen content. These plants also supported more aphid growth, in terms of fecundity and growth speed. Bell (2011) also demonstrated that these plants are likely to have reduced photosynthesis rates, similarly reduced growth, and even an increased susceptibility to frost. Nitric oxides seem to be the primary culprits for these effects. All of these data illustrate how seemingly small changes in the soil nitrogen levels affect both plants and animals within the ecosystem. This research suggests that the recycling center may impact the environment by increasing local vehicular traffic.
Furthermore, the process of recycling can, itself, be detrimental. For example, caustic chemicals are used to remove ink from paper so that it can be recycled, which leaves behind a mixture of toxic chemicals and heavy metals. These waste products may run off into the surrounding water areas, and whatever has not escaped into the immediate environment is put into landfills (Bauer, 2011).
In this study, we collected a number of soil samples from around the MSU recycling center and the neighboring Baker woodlot, and analyzed them for various substances—such as pH, nitrogen, and aluminum. The hypothesis was that the MSU recycling center would alter the soil composition both in the locality of the facility and in the nearby woodlot. This hypothesis can be broken down into three assumptions: 1) if the recycling center is affecting the soil in that locality, then soil composition at the recycling center will differ from natural soil that is protected from anthropogenic change; 2) if the soil is affected by vehicle emissions due to its proximity to Farm Lane, then soil composition of Baker woodlot samples will correlate with distance from the road; 3) if the soil at the edge of Baker woodlot is affected directly by the recycling center, then the woodlot soil composition will be similar to the samples taken from around the center. Furthermore, we predicted that the pH level and nitrogen content of the soil would both rise as distance from Farm Lane decreases. Similarly, we predicted elemental levels to be higher in samples taken from around the dropboxes than other samples due to the materials being stored there. Finally, we predicted that the pH level and nitrogen content of our recycling center samples—from around the drop off bins and from the facility perimeter—will be higher than that of our woodlot samples, which will be higher than those of our controls, which were taken from the interiors of Baker woodlot and Sanford Natural Area.Continued on Next Page »