Table 1 Main characteristics of the studies included in the review

Rihmer, 2015

Hungary

2005-2011

1639 settlements divided in:

(I) 5871^a

(II)5017^a

(III)3066^a

(IV)4373^a

(I) Low 10 μg/l

(II) Intermediate 11–30 μg/l

(III) High 31–50 μg/l

(IV) Very high >50 μg/l

(I) – 23.6 (18.4)

(II) – 30.6 (17.2)

(III) – 32 (17.7)

(IV) – 33.8 (21.4)

P < 0.001

Pompili, 2017

Italy

−1980–2011 (analysis of suicides rates)

−2009–2010 (collection of water samples)

145 sites

157 water samples

104 provinces

0.969 μg/l CI 0.543–1.396 μg/l

7.53^b