Another way to collect a stool sample is to loosely place plastic wrap across the rim of the toilet, under the seat. Then place the stool sample in a clean, sealable container before taking to the laboratory. Plastic wrap can also be used to line the diaper of an infant or toddler who is not yet using the toilet. The stool should be collected into clean, dry plastic jars with screw-cap lids.
The potential variations in the properties of agricul-. tural soils are less well known. Diaz et al. (1994) have. reported that under a climate change scenario the soil. organic matter content and erosion rate would de-. crease with regard to current values in the Arrecifes. River basin.
You are correct that climate including the effects of altitude affect seasonal allergen exposure. In general, drier environments have less allergen levels due to less growth of the plants and fungi that produce seasonal allergen, pollen and spores. Measurements of these airborne particles demonstrated that the outdoor levels are influenced by temperature, wind direction, humidity and rainfall and light exposure.