4.5 Answer the questions to the text.

1. What is environmental chemistry?

2. What causes acid rains?

3. What are the effects of acid rains?

4. What is the main component of acid rain?

5) What harmful ways are used to boost crop yields?

6) What is the effect of residual pesticides on human health?

7) Are toxic and persistent pesticides still used in agriculture? Why?

4.6 Match the words with the definitions:

1. to preserve	a) an amount of gas or other substance that a machine or factory produces and sends into the air
2. emission	b) a chemical substance used to kill insects or small animals that destroy crops
3. contaminant	c) happening once a year
4. pesticides	d) unwanted materials or substances that are left after you have used something
5. annual	e) a poisonous substance that makes something impure
6. waste	f) a type of animal or plant that may soon no longer exist
7. endangered species	g) to save something or someone from being harmed or destroyed

4.7 Fill in the gaps using the words given below the text:

Air pollutant is any … in air that could, in high enough concentration, harm human beings, animals, vegetation, or material. Pollutants may include almost any natural or … composition of matter capable of being airborne. They may be in the form of solid particles, … droplets, gases, or combinations of these states. Generally, they fall … two main groups: a) those emitted directly from identified sources and b) those produced in the … by interaction between two or more primary pollutants or by reaction with normal atmospheric constituents, with or without photoactivation. Exclusive of pollen, fog, and dust, which are of natural … , about 100 contaminants have been identified. They fall into the following … : solids, sulphur compounds, volatile organic chemicals, nitrogen compounds, oxygen compounds, halogen compounds, radioactive compounds, and odors.

artificial, liquid, origin, substance, into, categories, air

Text 5 Organic agriculture

5.1 Read the following international words and translate them: alternative, activity, collection, minimize, method, traditional, rotation, practice, management, enzymes, antibiotics, hormones, balance, producer, analysis, commercial, respect.

5.2 Translate the following word-combinations into Russian: Earth’s precious water supplies, home pest control, lawn care, US agriculture research dollars, soil quality, soil structure, water infiltration, water-holding capacity, crop rotation, pest-and-disease resistant varieties, soil fertility, crop production.

5.3 Read and translate the text with the help of a dictionary.

The production and use of organic food products has taken firm root today as a serious alternative for consumers and farmers. Particularly since the early1990’s, a growing number of North American farmers have taken steps to minimize the use of toxic and persistent pesticides by establishing organic agricultural practices. Organic agriculture is a collection of tested agricultural practices by diligent farmers intent on preserving the health of our planet. Organic agriculture is sustainable, keeping soils healthy and alive, and helping to minimize contamination of the earth’s precious water supplies. Consumers who want to minimize their exposure to toxic and persistent chemicals can do so by buying foods and organic fiber products, and by choosing organic agricultural methods for home pest control and lawn care.

D

Center for Organic Agriculture

espite the fact that less than 1 percent of U.S. agriculture research dollars are spent on organic practices, organic production has been shown to have yields comparable to, and sometimes higher than, conventional systems. In additional, because organic production improves soil quality as measured by soil structure, organic matter, biological activity, water infiltration and water-holding capacity, organic systems generally produce higher yield than crops grown using conventional high-input methods during drought, leading to production stability year after year.

Organic farming appears very much like traditional farming. The main difference is in the use of chemicals for treatment and nourishment. Organophosphates are not allowed in organic agriculture. Instead, organic growers use biological and cultural practices as their first line of defense against pests. Methods used include crop rotation, the selection of pest- and disease- resistant varieties, nutrient and eater management, the provision of habitat for the natural enemies of pests, and release of beneficial organisms to protect crops from damage. Organic pesticides of molasses and enzymes are sprayed to ensure a healthy crop production.

Organic pesticides prohibit the use of genetic engineering, irrigation, sewage sludge, antibiotics, and hormones. These practices are allowed in other forms of raising and producing our food, and other agricultural products.

Because organic agriculture respects the balance of microorganisms in the soil, organic producers use composted manure and other natural materials, as well as crop rotation, to help improve soil fertility, rather than synthetic fertilizers that can result in an overabundance of nitrogen and phosphorous in the ground.

Current conventional practices have led to some measurable problems, including a high level of toxic metals in commercial fertilizers. An analysis of 29 fertilizers found that each contained 22 different heavy metals. In 20 of the products, levels exceeded the limits set on wastes sent to public landfills, with disturbing quantities of arsenic, lead, mercury, cadmium, chromium, and dioxin, among others.

5.4 Give English equivalents: трудолюбивый фермер, сохранить здоровье, запасы воды, общепринятые методы, традиционное земледелие, севооборот, принимать меры, полезные организмы, переизбыток азота, тяжелые металлы, во время засухи, превышать уровень.