Figure 7
From: Human health risk of nitrate in groundwater of Tehran–Karaj plain, Iran
Comparison of the median nitrate concentrations in 75 wells sampled in the first three years and those that measured during last three years of the study period The dash green line determines the permissible level of nitrate for drinking water, i.e. 50 mg/L, as suggested by World Health Organization (WHO)37. This figure was prepared in Microsoft Excel.
