Continued nitrogen emissions by various sources of pollution pose a risk to groundwater and
have become a widespread problem worldwide (Samuel Mattern et al. 2009; Rodvang and
Simpkins 2001; Burow et al. 2010; Panagopoulos et al. 2011). Over the past few decades,
excessive use of nitrogen has caused agricultural non-point source pollution to become one of the
most important modes of contamination of regional groundwater. According to 2004 statistics,
China is the world’s largest fertilizer producer and consumer. In 2002, a total of 142 million tons
of fertilizer were consumed worldwide, with 43.395 million tons being consumed in China (Zhu
Zhaoliang and David North 2004). This large-scale use of chemical fertilizers has led to
increasing groundwater nitrate pollution. According to the findings of the Chinese Academy
of Agricultural Sciences in the five provinces of the northern 20 counties in more than 800
survey sites, the groundwater nitrate content of 45 % of the survey points (N) was greater than
11.3 mg/L, while it was more than 20 mg/L at 20%of the sites and higher than 70 mg/L at some
individual survey points (Zhaoliang and North 2004). It has been reported that a drinking water
nitrate nitrogen content of more than 10 mg/L can cause methemoglobinemia (Federal-
Provincial Working Group on Drinking Water (Canada) (Health and Welfare Canada 1979). A
geological survey of Shenyang in 2009 and 2010 indicated that the groundwater in the study area
currently has a groundwater nitrate content (N) range of 0–157.02 mg/L, and that areas
characterized by excessive groundwater nitrate include sewage irrigation areas, which are
common sources of agricultural pollution. Groundwater nitrate pollution is threatening human
health and safety; therefore, it is necessary to expand the health risk assessment of groundwater
nitrate pollution and provide a reference for groundwater management and pollution prevention.