Deborah Swackhamer talks to Kathryn Lees and Neil Withers about water pollution. Deborah Swackhamer is professor of environmental chemistry at the University of Minnesota. Her work focuses on water pollution, in particular, on the chemical and biological processes that control the fate of toxic organic contaminants in the Great Lakes of North America.
Read the conversation and discuss the problems mentioned in it. Neil Withers: What is the focus of your research?
DS: When I was a graduate student I saw the Great Lakes for the first time - I was stunned by their size and beauty. As a result, I spent my graduate work understanding the chemical behaviour of the Great Lakes and, ever since, I've focused on water chemistry programmes of the Great Lakes basin. Because the Great Lakes act like fresh water oceans, you can understand global processes by studying them. They're also easily accessible and urbanized - 42 million people live in the basin so they're reasonably polluted.
KL: What are the main pollutants in the Great Lakes?
DS: There are still 'legacy pollutants' such as DDT coming from atmospheric deposition as well as phosphorus and nitrogen from agriculture and sewage. However, the new problem is with endocrine disruptors. We know little about where they're coming from but we know they're causing harmful effects. At present, they are impacting fish and bird life but we are not sure if they are affecting people who are drinking the water.
NW: What is the greatest threat to the Great Lakes?
DS: In addition to the chemicals, biologically, there are close to 200 invasive species and a new one is added every eight months. The impact on food webs and ecology could be enormous. However, a dominant factor is the physical threat of global climate change. It affects how chemicals behave in the environment and it drives change in an ecosystem too. Everything is interrelated.
KL: Which species make good biomonitors in the Great Lakes?
DS: A salmon lives for three years and grows to one metre so they take up a lot of chemicals. They're also easy to catch and analyze so they give you a good sense of what's in the water.
NW: Many of the pollutants you mentioned are of great use to many people - how can we find a balance?
DS: Part of the problem is that our regulatory systems for evaluating chemicals are not rigorous enough. The US Toxic Substances Control Act (TSCA) was meant to regulate toxic compounds, but they have allowed many harmful chemicals through their regulatory 'filter'. We need better modeling tools for predicting toxicity and environmental behaviour so that we can design chemicals that will benefit society and not hurt the environment.
Soil Pollution “The problem is the way we are thinking.
The problem is fundamentally a cultural problem.
It's at the level of our culture that this illness is happening.”
~ Thom Hartmann
Soil pollution is particularly dangerous for the environment and our health because soil, either in the mountains or in the plains, contains the largest part of the water we drink and produces all the food we need.
1. Give the Russian equivalents to the following words:
productive, texture, associate, insecticide, erosion, phosphorus, calcium, magnesium, manufacture, protein, stable, alternative, pheromone, hormone, sterilization, radiation, packaging material, battery metals, temperature extremes, construction, medicinal substances
2. Guess the meaning of the underlined words. Translate the sentences.
1) Soil erosion occurs when topsoil moves from one place to another as a result of various natural and man-made factors. 2) Water is one of the most essential ingredients that are required for the normal growth of crops. 3) The salts present in the water accumulatein the top layer of the soil, resulting in decreased growth of crops. 4) Excessive use of chemicals such as pesticides, insecticides and fertilizers is one of the prime factors causing soil pollution. 5) If prevention is not possible there are also standards in place for clean up of polluted soil. 6) Another method is excavation where the contaminated soil is taken away. 7) Harmful substances may be introduced to the soil through water that has been in contact with the soil.
3. Translate the following word combinations:
rocky surface; decayed remains; uppermost topsoil; over thousands of years; weathering of bedrock; sufficient food; to disturb the biological balance; large quantities, necessary nutrients; to correct soil deficiencies; over the years, protein content; unwanted populations; domestic refuse; hazardous substances; smelting industries; weathered soil particles; intact and healthy; innumerable food chains; a cure for cancer and aids
4. Match the word from list A with its definition in list B.