The sprinkler family of irrigation devices â used for about 15% of farm irrigation â is a bit better than flood irrigation in terms of efficiency, but thatâs not saying much. Bringing up the rear in terms of usage is drip irrigation, which is the method of choice for about 5% of farms.
The ready-to-eat cafeteria foods were also found to be contaminated with Escherichia coli, Staphylococcus aureus and Streptococcus faecalis at similar rates (Table 2). Up to half of the ready-to-eat foods were contaminated with two or more strains of these pathogenic bacteria (data not shown).
What is biological contamination in food? Biological contamination occurs when foods containing naturally occurring substances that are poisonous to humans are ingested; such solanine in green potatoes, oxalic acid in â¦ the leaves of rhubarb and some type of mushrooms.+ 22 others found this useful. biological contaminant that is one of the biggest sources of air  pollutionis mold. Molds can be found everywhere and mold spores are  common components in household and w â¦ orkplace dust.