Residents living near a landfill site say their physical and mental health are suffering because of the smell.
The odour given off is causing stress, anxiety and sleeplessness, Public Health England said.
The Environment Agency (EA) said hydrogen sulphide levels recorded at the site exceeded World Health Organization guidelines.
Waste management company RED Industries said it is “acutely aware of the communities’ concerns” and work is underway to “seal an extensive area of the site.”
BBC Midlands correspondent Phil Mackie spoke to residents about the Silverdale stink.