Nigel Adams has spoken on The One Show regarding the problem of the rubbish pile in Great Heck.
See 3 minutes in for his take on the situation and what needs to be done urgently:
The EA say they are monitoring the air and this will include chemical analysis of the fumes. They are also in contact with Dept of Health who will assess whether there is a health risk associated with breathing the fumes and what concentration constitutes a risk.
If you do feel ill and your doctor says there is a possible linkage to the smell, you are encouraged to ask them to report it to the Department of Health.