Government trying to kill us off as too many living in uk?

A woman i work with has been telling everyone that our government is trying to kill people off by putting chemicals into the air. She explains that's why people are sick all the time. She also says that they put a certain chemical around the inside of tins of beans and various other tinned food. Cigarettes are another thing she tells us are altered with. This woman is quite pessimistic and is quite depressing to be around. Everyone at work says its a load of deluded nonsense and to ignore her but she keeps going on about it. She says that no one harldy knows about it because nobody cares whats happening. She tells me to google it, but i don't think i want to! I think i'm happy being ignorant to all of this. Is this true, partly true, or is this woman loosing it?