A laboratory simulation of the potential groundwater contamination associated with burial materials

Abstract

Metals, coatings and embalming fluid used in burial practices may corrode and seep into the soils, which could end up in nearby water sources. However, this basic assumption has not yet been proven. To avoid other anthropogenic factors, this thesis comprised of a laboratory study of the leaching potentials of metals and formaldehyde through different soils under various environmental conditions. After collecting and analysing the coffin samples, twenty-seven containers with taps were filled with either sand, silt or clay soils. Samples of burial materials, cloth saturated with formalin and bacteria were buried within each soil column. These were exposed to high or lower temperatures and conditions simulating heavy or prolonged rainfall using either acidic or slightly acid water. Interment continued for six months. In addition to testing the effects of these variables, cement was buried in the three soil types with pre-weighed coiled wires of common metals, namely aluminium, iron, copper and zinc. After 24 weeks of testing, the corrosion rates of the various metals were determined, which allowed us to conclude that concrete tombs could be a possible solution to reduce the corrosion rates of coffin materials. It may also retard soil and groundwater contamination. After analysing the water leachates of each sample, it became evident that coffin materials do indeed corrode and become mobile. It also verifies that the aforementioned variables do in fact affect the corrosion rate and leaching of the various coffin materials and that concrete tombs truly are a solution to reduce corrosion and contamination rates of cemeteries. The results also showed that most formaldehyde percolated through the soil between weeks six to week 14 of interment. Neither temperature nor pH affected the amount of formaldehyde leachate, however, conditions simulating heavy rainfall facilitated leaching. Although a total of only 3% of the initial amount of formaldehyde became mobile, concentrations of up to 15.0 mg/L formaldehyde were recorded on two occasions – considerably higher than the Tolerable Concentration recommended by the World Health Organization.