Environmental Chemistry

Tutorial #1

Chemicals in Your Body Your body needs nutrients (chemicals) to

maintain function Two types of nutrients

Organic Inorganic

Organic Nutrients: Contain carbon Are essential for your health Things like carbs, proteins, lipids & vitamins

Inorganic Nutrients These are minerals Two types of minerals

Macrominerals – 100mg/day or more Trace Elements- <100 mg/day

Minerals Components in enzymes (protein molecule that regulate

chemical reactions in living things)& vitamins (lg organic molecules that help enzymes to function)

The human body can’t make vitamins, we must get them from the food we eat. We require 22 different ones for growth and function. See table 3.2 pg 180 in text.

Where do we get these minerals and vitamins? Most elements we need are in the soil. Eating soil won’t help because we need higher

concentrations of the minerals. Plants extract minerals from the soil in their roots. When we eat the plants we access the organic

compounds they have extracted. Without plants we aren’t able to obtain the

nutrients we need. ie: Scurvy This is why scientists study plants and why they

are so important!

Plants & Fertilizers Plants & their growth are affected by the amt. of

nutrients they can extract from the environment. Plants require:

Phosphorus (for seed germination) Nitrogen (stem and leaf growth) Potassium (promotes flower and fruit formation)

# on fertilizers tell you how much of each nutrient is in the bag. ie:21-7-7 (N, P, K)

Pesticides Three types:

Herbicides (weeds) Insecticides (insects) Fungicides (fungus)

All pesticides help control other species that compete with our crops.

This can create trouble! The citronella candles you burn,keep mosquitoes

away but pesticides actually kill the affected species.

Trouble with Pesticide Initially, when these were used, it was thought to be a

wonderful thing and but the impact was not immediately recognized.

DDT – is an insecticide (poison) DDT was used to kill typhus (transmitted by lice) because

typhus wiped out Napoleons army in it’s retreat from Russia in 1800’s

In fact, it’s inventor won a Nobel Prize for it’s efficiency in controlling pests.

In the 1950’s it was hoped DDT would help wipe out Malaria. It did, but it also affected the entire food chain

DDT’s Affects DDT – stays in the environment for a very long time If consumed, it accumulates in bodies of living things and

eventually kills them. Animals in food chains were vastly affected and populations

of predatory birds was decreased. It was found that DDT reduced the ability of these birds to

produce normal egg shells… This process in called BIOMAGNIFICATION DDT is still used in some tropical areas because benefits

outweigh the risks with regard to malaria and no substitute has been found.

Pesticides New pesticides are being created and

tested all the time. Our efforts are being compromised by

pesticide resistance. This creates problems for us in the future

not to mention our health! In comes: the organic food…