Hauxton Clean Up
The Health Protection Agency says work to clean up some contaminated land in Hauxton is "very unlikely" to pose a risk to human health.
The organisation has monitored the quality of air around the old Bayer Crop Science site for 28 days.
Since the work began in March, the HPA has continued to advise that substances released into the air by the work are very unlikely to pose a risk to the health of people nearby.
Since the 1940s, the site, near the A10, was used to produce chemicals like pesticides and herbicides.
Over time, these materials contaminated the surrounding soil and are also threatening two nearby rivers.
Because of this contamination, Harrow Estates and South Cambridgeshire District Council are working to clean up the land before houses are built on it.
Since the de-contamination work began, residents have been complaining of chemicals being released into the air causing breathing difficulties, sore throats, streaming eyes, burning lips and numb tongues.
Kevin Rutterford, from the Environment Agency said: "The HPA is doing a very thorough job of analysing the results from the air quality monitoring, which is a very important part of this project.
Everyone involved with the site is working hard to minimise the nuisance odours caused by the clean-up work, but to safeguard our environment into the future, this work must be carried out now."
A protest group, called Haux-Air, has been set up by residents who believe the work is damaging resident's health.
The Haux-Air website claims that: "The clean up process itself is causing problems for the local residents in 10 or so villages – Hauxton, Harston, Haslingfield, Gt.Shelford, Lt Shelford, Stapleford, Grantchester, Barton, Trumpington, Barrington.
Not only is there the nuisance of almost unbearable noxious smells and dust, but there does seem to be an increase in the number of people with symptoms such as breathing difficulties, sore eyes and throats, burning lips and numb tongues particularly when the wind blows their way."
Jennie Daly, from Harrow Estates which is carrying out the work, said: "The Health Protection Agency has advised that Volatile Organic Compounds (VOC) emissions from the site are not of concern toxicologically and are therefore very unlikely to pose a risk to the nearby residents short or long term health"