What's in biosolids
Biosolids are sewage solids that have been treated to eliminate harmful bacteria and reduce odours. Biosolids can also contain small amounts of other materials that come from household items and personal care products that we use, such as medications, soaps and shampoos. These products enter the wastewater system through our sinks and toilets.
Do biosolids contain harmful materials?
To help answer this question, Metro Vancouver commissioned a human health risk assessment, which showed that human health risk from typical biosolids use is very low. For example, it would take 3,000 years for a worker applying biosolids to land 220 days/year to be exposed to the amount of the antibiotic ciprofloxacin that is considered harmful to human health. To look at it another way, it would take a child over 266,000 years of playing near, touching and digesting biosolids to be exposed to the amount of ibuprofen contained in one tablet of over-the-counter pain relief medication.
The compounds found in Metro Vancouver's biosolids are present in everyday items that most of us use on a daily basis and at much higher levels than are present in biosolids. As technologies improve, it is possible to measure these materials in biosolids in even trace amounts. However, research shows that the level or concentration of compounds is so low that it would take multiple lifetimes of working or playing around biosolids to equal everyday exposure to many common products, such as antimicrobials found in soaps and toothpaste, flame retardants found in fabrics, and pain relief medication.
Exposure to Biosolids Compared to Use of Common Products
It would take many years of working or playing around biosolids or landscaping soil containing biosolids to equal exposure to many common products.