refined it again after following the new Leads and added the word PROBLEMS to the search.
I entered each site and copied the HITS to a MS WORD document.
and building the content.
natural gas 1
Israel Electric Corporation 1
M. Shechter 3
main sources of air pollution 4
vehicular traffic 4
sulfur dioxide emissions 4
power plant and oil refineries 4
health damages 5
water pollution 5