The health department said that lab tests are being done on food and environmental samples as well.

MSN: Texas recalls all products linked to peanut plant

They would collect environmental samples such as soil, rubble or vegetation that may have been in contact with the chemical warfare agent and may still contain characteristic degradation products or even traces of it.

BBC: How to investigate chemical weapons allegations

's International Atomic Energy Agency asked Iran to explain the presence of particles of enrichment levels of up to 27%, found in an analysis of environmental samples taken in February at the Fordo fuel enrichment plant near the city of Qom.

CNN: Talks over Iran's nuclear program resume in Moscow

Full results from environmental swipe samples taken in June from the bombed site are due to be released within 3 weeks.

BBC: Shooting delays UN Syria inquiry

It also stated that nearly 13% of sea-bed residue samples from fish farms were higher than the environmental standard allowed.

BBC: Scotland's fish farming faces stricter controls

The U.S. Environmental Protection Agency's drinking-water regulations require that all samples test negative for E.coli.

CNN: Soda fountains contained fecal bacteria, study found