VCE Environmental Science

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What is the difference between bioaccumulation and biomagnification? Read an interesting article from the Scientific American – “Bald eagles succumb to poisin in rat eradication on Alaskan island” . Is this an example of bioaccumulation or biomagnification?

Local examples of bioaccumulation from the Australian government department of environment, water, heritage and the arts – uranium in freshwater mussles and fish in the Northern Territory. Bioaccumulation of copper and tungsten in northern Queensland. What types of toxins are most likely to bioaccumulate and biomagnify?

“Almost all mercury compounds are toxic and can be dangerous at very low levels in both aquatic and terrestrial ecosystems. Because mercury is a persistent substance, it can build up, or bioaccumulate, in living organisms, inflicting increasing levels of harm on higher order species such as predatory fish and fish eating birds and mammals through a process known as “biomagnification”. Although the long-term effects of mercury on whole ecosystems are unclear, the survival of some affected populations and overall biodiversity are at risk.” from Mercury and the Environment. Another resource about mercury in our environment here: “Methylmercury Contamination in Fish and Shellfish.” Health effects of mercury here: “Mercury in the body and health effects“.

Photo Source - Most of the anti-fluoride protest is scare-mongering and irrational – note the swastika!

As I will be with the Year 9/10 camp, at Rubicon during the first week back at school, you will need to work through Chapters 1 and 2 in class. The Area of study is pollutants, with case studies of mercury, sulphur and fluoride. In the previous post there are some worksheets for you to download and complete.

You may have heard about fluoride in the news recently – there have been bomb threats to Barwon South West Water and a Victorian MP is under police guard after fluoride has been intoruduced to Geelong’s water supply. Warrnambool received fluoride in the water supply last year after many months of contentious debate. Some people claim it is poison, while many scientists and dentists believe it reduces the incidence of tooth decay. Should we consider it as a pollutant?

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U.S. researchers have reported that dust from the moon is toxic – the fine particles are electrostatic, chemically active and sharp-edged. Lunar astronauts reported irritation and discomfort from exposure to dust, with symptoms ranging from sneezing, watery eyes and a peculiar smell resembling gunpowder, says NASA flight surgeon Jeff Jones. A flight surgeon, who was also exposed to the dust, reported an allergic reaction – irritation, sneezing, irritated mucus membranes in the eyes and nose.

This may not seem relevant (unless you are planning a trip to the moon any time soon), but you may also be exposed to the dangers of fine particulates in environments on earth. For example, mining sites, bushfire zones, factories and industrial sites may require protective clothing and breathing apparatus to be worn to prevent exposure to dust and/or toxic gases. Fine particles, known as PM₁₀ (particular matter smaller than 10 um in diameter), can impact on people’s health especially those that have existing respiratory or heart disease. Children and the elderly may also be more vulnerable to the effects of particles.

Mesothelioma refers to a rare form of cancer of the mesothelium, caused by exposure to asbestos – usually by inhaling or ingesting the fine particles and fibres which become lodged in the lungs. Asbestos is a mineral that was once widely used due to its fire resistant and insulating properties, but is no longer mined, milled or manufactured in Australia because of the health risks. All uses in new products are now banned in Australia and no asbestos products may be imported. Strict precautions also govern the removal and disposal of asbestos and asbestos-containing materials.
EPA – Air quality, Airwatch program.

This is an ideal case study for Unit 4. It incorporates knowledge about point and diffuse sources of pollution, bio-accumulation of heavy metals and other persistent pollutants, a variety of stake-holders with different perspectives and the state regulatory bodies and their policies. You can find out further information at the following sites:

The Age: Dredging the Bay This is an excellent interactive site that has seven short movies, including a diver’s perspective and images of the Phillip Island penguins. It also has three animations about how and why the bay will be deepened and the impact of dredging.

Office of the Environmental Monitor
Established in December 2007 by the Victorian Government, the Office of the Environmental Monitor provides an around-the-clock independent and transparent view on the environmental performance of the Channel Deepening Project. The web site is a one-stop-shop for information on the Office, results from the 20 plus monitoring programs operating in Port Phillip Bay and and general information relating to Channel Deepening Project. The Office is a major stakeholder in the Project and students could find the fact sheets and results on the website useful.

Port of Melbourne: Channel Deepening Project Including the Environmental Management Plan, latest news and weekly turbidity.

Blue Wedge Coalition The community group in oppostition to dredging the bay has fact sheets, frequently asked questions and a student section.

Environmental Protection Authority of Victoria has several pages with information about their role in the project – including a Supplementary Environmental Effects Statement.

The National Pollutants Inventory has a List of Substances that are considered to be important pollutants.