Over the last several years contributions to PEQ have increased considerably. As a backlog of articles was building, it felt appropriate make some changes content journ...

abstract fluoride (f-) is an essential element for human and some animals. the fluoride concentration in irrigation water is an important index for water quality. the objective of the present study was to determine spatial variability of fluoride in groundwater and soils of some areas in arak plain. therefore, during two seasons, autumn (2007) and the end of spring (2008), 87 and 92 water sampl...