Turbidity of drinking water supplies in relation to incidence of gastrointestinal illness
Several epidemiological studies investigated the association between turbidity of drinking water supplies and incidence of acute gastrointestinal illness (AGI). Researchers conducted an up-to-date review on this topic, including a synthesis of the overall weight of evidence. They identified 14 studies on the topic (distinct by study region, time period, and/or population) and found multiple studies linking water turbidity and AGI incidence. These associations were found in different cities and with different types of water treatment. The research results of this analysis suggest that exposures to microbial contamination through drinking water caused a low, but detectable, number of AGI cases in the regions and time periods studied. Scientists are hesitant to claim that the exposure caused the illness, however, there is no clear alternative explanation for the patterns of association.