Is it safe to work in a bus garage while pregnant?

I work in a busy bus garage as a cleaner. I have to clean buses top to bottom so they can be serviced, It is a very physical job and i have to carry lots of heavy buckets, hoovers and cleaning Equipment up double decker stairs also i have to remove all chewing gum and rubbish and always be aware of needles and other sharp objects and have to clean up smashed gl and vomit etc. The buses are in a busy garage as mechanics are working on them at the same time. The garage has oily floors and wet slippery surfaces with 6ft deep pits there is also a constant smell of oil, diesel, welding fumes and our cleaning chemicals. My boss hasn't done a risk essment and i was wondering other peoples opinions. thank-you