Aircraft noise affects cognitive development in children

Everyone finds unwanted noise annoying, but children may be especially vulnerable to its effects, partly because they cope with stressors less well than adults, and partly because noise might interfere with learning at a critical developmental stage. Children may react by tuning out unwanted noise and, in the process, pay less attention to other inputs, such as a teacher's speech. A new study adds to the developing literature on the negative effect of noise on learning.

The study used over 2800 children aged 9-10 years, attending schools located near three major airports in Spain, the Netherlands, and the United Kingdom. The investigators assessed level of noise caused by aircraft and traffic around the school, and related these levels to the results of cognitive performance testing and health questionnaires. Chronic exposure to aircraft noise had deleterious effects on reading comprehension even after adjustment for socioeconomic differences between high noise and low noise schools (figure). A limitation of the study is its cross sectional design, but the results show, perhaps unsurprisingly, that schools in noisy places are less than ideal educational environments.

Lancet 2005;365: 1942-9

GI endoscopy is not a route for transmission of hepatitis C virus

Surgical operations are one way in which the hepatitis C virus (HCV) is transmitted and, even though the evidence is weak, a faint cloud of suspicion hangs over less invasive procedures too. In Italy and France, for example, blood donors are turned away if they have had a recent gastrointestinal endoscopy. The results of a large prospective study from Italy now show that this procedure is blameless.

The investigators measured the incidence of HCV seroconversion in more than 9000 patients from three centres in the six months after endoscopy and in a large comparison group of blood donors. In two of the centres, biopsy specimens were taken with reusable forceps. Although a small percentage of …