title: Does water hardness have preventive effect on cardiovascular disease?
abstract: BACKGROUND
  The aim of this study is to investigate the association of calcium and magnesium concentration of drinking water with cardiovascular disease (CVDs) in urban and rural areas of a city in Iran.
  
  
  METHODS
  This case-control study was conducted in 2012 in Khansar County in Isfahan province, Iran. We used the official data of the Provincial health center regarding the chemical analysis data of urban and rural areas including the hardness, calcium and magnesium content of drinking water. Data of patients hospitalized for CVD in the only specialty hospital of the city was gathered for the years of 2010 and 2011.
  
  
  RESULTS
  In 2010, water calcium content above 72 mg/L was associated with reduced number of CVDs in 1000 population; whereas in 2011 this decrease in CVDs was observed for calcium levels of more than 75 mg/L. In 2010, the level of water Mg content ranged from 23 to 57 mg/L. By increasing Mg hardness level above 31 mg/L in 2010 and above 26 mg/L in 2011 were associated with decreased number of CVDs in 1000 people. decrease.
  
  
  CONCLUSIONS
  Our study suggests favorable protective effects of water hardness, mainly water magnesium content, on CVDs. Water hardness, as well as calcium and magnesium content of drinking water may have a protective role against CVDs. Further experimental studies are necessary to determine the underlying mechanisms and longitudinal studies are required to study the clinical impacts of the current findings.
authors.affiliation: Department of Environmental Health Engineering, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Mitra
authors.initials: M
authors.lastname: Momeni
authors.affiliation: Department of Environmental Health Engineering, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Zahra
authors.initials: Z
authors.lastname: Gharedaghi
authors.affiliation: Department of Environmental Engineering, Environment Research Center, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Mohammad Mehadi
authors.initials: MM
authors.lastname: Amin
authors.affiliation: Department of Environmental Engineering, Environment Research Center, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Parinaz
authors.initials: P
authors.lastname: Poursafa
authors.affiliation: School of Public Health, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Marjan
authors.initials: M
authors.lastname: Mansourian
keywords: Calcium; Iran; cardiovascular disease; magnesium; water hardness