Team:York/Sustainability

Sustainability

Define: Sustainable
Line breaks: sus¦tain|able
ADJECTIVE: Able to be maintained at a certain rate or level

The nature of democracy is one of fast but short-term improvement as policy makers have only a matter of a few years in which to prove themselves. This is reflective of human nature: we crave instant gratification at the cost of long-term improvement. However, today more than ever before it is clear how powerfully our actions impact our future. We need to build a more sustainable society. Our project aims to improve environmental sustainability of important industry by making the processes they use less environmentally damaging in the long run. However, part of what makes planning every project so challenging is that to be truly sustainable, it must be sustainable in every aspect. This is why our human practices are so important.

Cadmium in Global Waters

Acid sulphate soils are formed naturally in waterlogged conditions. They have formed around the world as sea levels have been changing over the past thousands of years. These soils are formed when waterlogging creates anaerobic conditions in which naturally occurring bacteria convert sulphate into sulphide. These soils are not harmful as they are, however, if water is removed from the area and the sulphide is exposed to the oxygen, they oxidise to produce sulphuric acid.

The sulphuric acid leads to a series of problems. It can seep into groundwater and soil where it can harm and kill wildlife. It can lead to the release of gases such as hydrogen sulphide, sulphur dioxide and methane. It also dissolves heavy metals such as cadmium, releasing them from the sediment and allowing them to become bioavailable in the environment. The serious problems caused by this release of heavy metals are covered in a following section.

Problems from acid sulphate soils result both from natural and anthropogenic activity. The soils form naturally but as sea levels rise and fall, they can also become naturally exposed to air. In areas where drought is common, a greater quantity than average of water can be removed from the soil by plants, resulting in more oxygen in the soil. A large number of industrial processes also result in oxidation of soils. Any process which requires land to be dredged or drained will result in oxidation of soils. This is common in agriculture and groundwater extraction. Mining is also extremely problematic as it not only results in oxidation of the soil, it also tends to release heavy metals and pollutants into the soils which add to the problem.

A primary example of where acid sulphate soils are a problem is coastal Australia. The iron sulphide layers are found in many low-lying areas along the coastlines of the Northern Territory, Queensland, and New South Wales, as well as along the northern coastline of Western Australia, around Perth, Adelaide, and Westernport Bay.

References

1. http://www.environment.gov.au - About Acid Sulfate Soils
2. http://www.dpi.nsw.gov.au - An introduction to Acid Sulfate Soils

Cadmium Contamination Effects on Humans

The main issues with cadmium getting into waterways and food supplies are the affects that it will have on the people who ingest it. The effects of cadmium poisoning can be devastating as it is a known carcinogen and can consequently lead to death if ingested in large quantities. The other l effects of cadmium ingestion include:

• Gastrointestinal effects such as nausea, vomiting, salivation, abdominal pain, cramps and diarrhoea[1]

• Anaemia due to the cadmium resulting in a lower level of iron intake in the gastrointestinal region, this is especially problematic if the affected individual already has low levels of iron intake in their diet^[2]

• Kidney damage is a common symptom of cadmium toxicity which further leads to a decrease in production of vitamin D[3]

• Osteomalacis and osteoporosis both of which lead sufferers to have increased chance of bone fractures and lower bone density [4]. This may be as a result of the kidney damage giving way to decreased levels of vitamin D. [5]

References

1. Buckler, H. M., Smith, W. D., Rees, W. D. (1986) Self poisoning with oral cadmium chloride. Br Med J. 292(6535), 1559–1560.
2. Kagamimiori, S., Watanabe, M., Nakagawa, H., Okumura, Y. (1986) Case- control study on cardiovascular function in females with a history of heavy exposure to cadmium. Bull Environ Contam Toxicol. 36 (4), 484-490.
3. Arisawa, K., Nakano, A., Saito, H. et al. (2001) Mortality and cancer incidence among a population previously exposed to environmental cadmium. Int Arch Occup Environ Health. 74, 255-262.
4. Shigematsu, I. (1984) The epidemiological approach to cadmium pollution in Japan. Ann Acad Med Singapore. 13, 231-236.
5. Kido, T., Nogawa, K., Yamada, Y., et al (1989) Osteopenia in inhabitants with renal dysfunction induced by exposure to environmental cadmium. Int Arch Occup Environ Health. 61, 271-276.