Contamination in drinking water and cancer risk

A study published on the Environmental research tries to provide answers

by Lorenzo Ciotti
Contamination in drinking water and cancer risk

Nitrate and nitrite contamination in drinking water and cancer risk: A systematic review with meta-analysis, study published on the Environmental research, explained: "Pollution of water sources, largely from wide-scale agricultural fertilizer use has resulted in nitrate and nitrite contamination of drinking water.

The effects on human health of raised nitrate and nitrite levels in drinking water are currently unclear. We conducted a systematic review of peer-reviewed literature on the association of nitrate and nitrite in drinking water with human health with a specific focus on cancer.

We searched eight databases from 1 January 1990 until 28 February 2021. Meta-analyses were conducted when studies had the same exposure metric and outcome."

Contamination in drinking water and cancer risk

The researchers then added: "Of 9835 studies identified in the literature search, we found 111 studies reporting health outcomes, 60 of which reported cancer outcomes (38 case-control studies; 12 cohort studies; 10 other study designs).

Most studies were set in the USA (24), Europe (20) and Taiwan (14), with only 3 studies from low and middle-income countries. Nitrate exposure in water (59 studies) was more commonly investigated than nitrite exposure (4 studies).

Colorectal (15 studies) and gastric (13 studies) cancers were the most reported. In meta-analyses (4 studies) we identified a positive association of nitrate exposure with gastric cancer, OR = 1.91 per 10 mg/L increment in nitrate ion.

We found no association of nitrate exposure with colorectal cancer or cancers at any other site. We identified an association of nitrate in drinking water with gastric cancer but with no other cancer site. There is currently a paucity of robust studies from settings with high levels nitrate pollution in drinking water.

Research into this area will be valuable to ascertain the true health burden of nitrate contamination of water and the need for public policies to protect human health." Water contamination, as well as other factors such as pollution and climate change are increasingly proving to be a constant threat to health, as well as the destruction of the environment and ecosystems.