adverse health effects start to occur at a blood lead level less than pgdl in children however no statistically significant difference in blood lead levels was observed between women living in gers and in apartments suggesting that lead exposure comes from several sources and not only from polluted air resulting from coal combustion however there is a lack of data concerning the different sources of lead exposure such as lead in paint and in toys lead and occupational exposure and lead in dust and soil and their impact on the health of the mongolian population