Groundwater chemistry, pollution and health risk assessment for nitrogen compounds. A case study in a suburban region of Romania

As groundwater is used as a source of drinking water, monitoring its quality is essential due to possible
adverse effects on human health. Nitrogen compounds (nitrates, nitrites, ammonia) within certain
concentration limits are natural components of the nitrogen cycle. Due to anthropogenic activities, high
concentrations of nitrogen compounds are released into groundwater. The aim of this study was to evaluate
the chemistry of groundwater in a suburban area in northeastern Romania, the sources of pollution with
nitrogen compounds (nitrates, nitrites, ammonium), and the non-carcinogenic risk to human health
associated with consumption in different groups age (women, men, and children) in the investigated region.
The results showed that the concentration of nitrogen compounds varies from 5.12 to 98.3 mg/L for nitrates,
from 0.008 to 85.2 mg/L for ammonium, and from 0.001 to 1.12 mg/L for nitrites. The maximum admissible
concentrations have been exceeding 25%, 40% and respectively 10% of the total analyzed samples
Bivariate graphs and Principal Component Analysis (PCA) were used to identify potential sources of nitrate,
nitrites, and ammonium pollution of groundwater in the study area. The non-carcinogenic risk assessment
for water consumption showed a hazard index (HI total) for nitrogen compounds in groundwater in the
investigated region, which ranged from 0.037 to 2.856 for men, between 0.054 and 3.427 for women,
respectively between 0.080 and 6.145, for children. Spatial distribution maps using the Inverse Distance
Weighting technique presented the geographical areas with the probability of groundwater contamination
with nitrate, nitrite, and ammonium and the areas that pose a risk to human health by consuming
groundwater in the study area for the three groups: men, women and children.