Prince Edward Island, for example, has already lost half of its topsoil since 1900. A lack of productive soil will mean a greater reliance on commercial fertilizers to produce our food. These chemicals are usually synthetic organic substances and they find their way into the food chain via the water which runs off the agricultural land. Through this runoff, these synthetic compounds get into the natural food chain with unforeseeable consequences. It is no longer used, but other pesticides such as dieldrin continue to persist in fish at relatively high levels.
Pesticides kill more than the target pest.
These chemicals usually become concentrated in the fat of animals which eat the insects, and then move up the food chain in ever greater concentrations. Also, when sprayed in an area with high winds they can be carried for a considerable distance. On the farm, commercial fertilizer is spread on soil to increase the growth of crops. Unfortunately, not all applied fertilizer is used or made available to the plants. Nitrates and phosphates which are not absorbed make their way into surface water, causing serious environmental problems for plants and animals which depend on this water.