Summary

This document discusses phosphorus, its role in the environment, and in the human body. It explains how phosphorus can be both beneficial and harmful, depending on its concentration. The document also highlights the importance of organic and inorganic compounds to our bodies. Discusses issues such as phosphorus reduction, excess fertilizer runoff, and the necessary nutrients in our bodies. This document is a set of notes for secondary school.

Full Transcript

‭Name:‬ ‭Phosphorus: friend and foe‬ ‭ ver 40 years ago, phosphorus was big news. Phosphorus, then a common ingredient‬ O ‭in household laundry detergents, was identified as the culprit responsible for the‬ ‭excessive growth of algae and aquatic plants in lakes and rivers. Too much phosphorus‬...

‭Name:‬ ‭Phosphorus: friend and foe‬ ‭ ver 40 years ago, phosphorus was big news. Phosphorus, then a common ingredient‬ O ‭in household laundry detergents, was identified as the culprit responsible for the‬ ‭excessive growth of algae and aquatic plants in lakes and rivers. Too much phosphorus‬ ‭can fuel the excessive growth of algae and weeds. Not only is the resulting green scum‬ ‭an unpleasant sight, but as the algae blooms die-off, their decomposition uses up‬ ‭dissolved oxygen in the water. Low levels of dissolved oxygen in water can lead to the‬ ‭death of fish and other aquatic animals. Some types of algae can also produce deadly‬ ‭toxins.‬ ‭ hen this problem was recognized, most‬ W ‭manufacturers reduced the phosphorus‬ ‭(phosphate) content in their detergents.‬ ‭However, phosphorus is also a naturally‬ ‭occurring element. It is abundant in Alberta‬ ‭soils, and small amounts are a necessary‬ ‭part of the aquatic food chain supporting‬ ‭algae consumed by small animals.‬ I‭n Alberta, the amount of phosphorus that‬ ‭municipalities and industries discharge into‬ ‭water bodies is regulated under the Alberta‬ ‭Environmental Protection and Enhancement‬ ‭Act‬‭. Through pollution prevention strategies,‬ ‭and by applying the latest technologies,‬ ‭municipalities and industries can‬ ‭significantly reduce the amount of‬ ‭phosphorus in wastewater. some municipalities in Alberta have implemented a‬ ‭phosphorus reduction program that has greatly reduced phosphorus discharged to‬ ‭water bodies. limiting phosphorus-laden runoff from lawns and agricultural land‬ ‭continues to require careful management of fertilizers, as well as the adoption of‬ ‭beneficial management practices.‬ ‭Tips for reducing Phosphorus Pollution from your Home‬ ‭‬ U ‭ se appropriate fertilizers and apply to areas according to product instructions.‬ ‭Prior to fertilizing, test lawns and gardens to ensure you are applying what your‬ ‭soil needs.‬ ‭‬ ‭Do not over fertilize. excess fertilizer can run off and pollute nearby water bodies.‬ ‭‬ ‭Pick up pet waste and dispose of it properly.‬ ‭‬ ‭Protect riverbanks and shorelines. Keep soil covered with vegetation to minimize‬ ‭erosion.‬ ‭‬ ‭Compost kitchen scraps rather than use a garburator. some types of food are‬ ‭high in phosphorus and may be great for your garden, but need to be kept out of‬ ‭the wastewater system.‬ Chemicals in our body Our body is made up of chemicals that we obtain from food. Digestion: breaks down the chemicals in the food (aka nutrients) into small, soluble molecules, which then pass through membranes into the blood vessels. In the blood, these nutrients circulate through the body to the cells where they are used for energy, growth, body building, and cell repair. These nutrients can be divided into two major groups, organic and inorganic. Organic Compounds 1. Organic substances: (carbon- containing) nutrients classified as: a) Carbohydrates b) Proteins c) Lipids d) Vitamins. - Only green plants can form many of the organic compounds, while animals modify others. Regardless of the dietary source, they are essential for health. Deficiencies... Vitamin C helps form the connective tissue that holds our skin, muscles, blood vessels, and other body structures together. Humans cannot make vitamin C within their own bodies. Scurvy, a disease resulting from a lack of vitamin C in the diet, results in bleeding gums, loss of teeth, and bruising. Although scurvy is not fatal, it decreases resistance to other deadly diseases. British sailors in the 1700s were referred to as “Limeys” because of the lemons (called “limes” at that time) they ate to avoid scurvy. Inorganic compounds 2. Inorganic substances: minerals that are not destroyed by cooking or exposure to air. Mineral requirements are distinguished by the amount needed: macromineral (100 mg/day or more) or trace element (less than 100 mg/day). These minerals are essential components in enzymes (special protein molecules that regulate chemical reactions in living organisms) and vitamins (large organic molecules that help the enzymes function). Page 180 Table 3.2 The Role of Elements in the Human Body Deficiencies... Goitre, a swelling of the thyroid gland at the base of the neck, is often caused by iodine deficiency. It is a common problem in many parts of the world, particularly where sea products are not frequently eaten. The Root Source If we can find some of our essential nutrients in soil, why don’t we just eat soil? Even if we could eat soil, it would do us little good. The elements are found in such low concentrations that we would have to eat enormous amounts of soil just to get the minimum amount of elements needed. It is a good thing that plants can extract the minerals for us — by some estimates as much as 6 000 000 000 t every year! Plants as a source of nutrients The root systems of plants are uniquely suited for extracting minerals. Roots are covered with tiny “root hairs” to increase the surface area for absorption. Minerals dissolved in the water are taken up and concentrated into the root hairs. The minerals absorbed by the roots move to other parts of the plant, where they are used to build organic compounds such as vitamins, proteins, and lipids. When we eat these plants, we access these valuable organic compounds. Plants are essential to our health and survival. Without plants, we would not be able to obtain the nutrients we need. That is why many scientists are interested in what affects the development and growth of plants.

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