Tanzanian mines
... that airborne silica exposure in Tanzanian mines is more than three hundred times the limit set by NIOSH in the United States?
... that airborne silica exposure in <b id="mwXQ"><a href="./Mining_industry_of_Tanzania" id="mwXg" rel="mw:WikiLink" title="Mining industry of Tanzania">Tanzanian mines</a></b> is more than three hundred times the limit set by <a href="./National_Institute_for_Occupational_Safety_and_Health" id="mwXw" rel="mw:WikiLink" title="National Institute for Occupational Safety and Health">NIOSH</a> in the United States?