July 6, 2012 Clippings

Children exposed to violence suffer health problems: Study

Children exposed to community violence may be traumatised up to a year after the event, which may carry long-term negative consequences for health, says a study. ”We know that exposure to violence is linked with aggression, depression, post-traumatic stress symptoms and academic and cognitive difficulties in the short term, but little is known about the long-term effects of such exposure,” said Elizabeth Susman, professor biobehavioural health, Penn State University, US.

The scientists from the Penn State and University College London, chose 124 children, aged between eight and 13 years and living in small city and rural communities, to participate in the study, the Journal of Adolescent Health reports. ”We focused on children who live in small towns, so you would normally not expect them to be exposed to a lot of violence. Also, these were healthy children without a history of reported maltreatment,” said Melissa Peckins, biobehavioural health graduate student from Penn State.

The researchers gave each of the adolescents a questionnaire, which identified their exposure to violence during lifetime and within the past 12 months, according to a Penn State statement. The adolescents were then given the beginning of a story and asked to complete it in front of two mock judges, whom they were told were evaluating their responses and performances for later comparison to those of other children the same age. Following the story-completion task, adolescents were also given a serial subtraction task.

The team measured the children’s stress responses by comparing the cortisol levels present in samples of their saliva collected before and after the stress test was administered. Cortisol is a steroid hormone, produced by adrenal gland and is released in response to stress. ”In males, we found that as exposure to violence increased, cortisol reactivity decreased, so cortisol reactivity was attenuated; it was a habituation effect,” Peckins said. The finding was not present in females. “In enduring stressful conditions, we may have adapted evolutionarily to suppress our cortisol levels because higher and more prolonged levels of cortisol in the bloodstream can lead to negative health consequences, such as autoimmune disorders, lowered immunity, arthritis and atypical depression,” Susman said.

This may explain why cortisol reactivity was lower for males,” Susman added. ”However, there is a theory that females may react to stressful situations by talking about it, which may be their way of reducing the negative effects of cortisol in the bloodstream,” Susman said.

Source: http://health.news.com             06.07.2012

Over half of inhaled diesel soot gets deposited in lungs

Soot particles contained in the exhaust from diesel-fuelled vehicles, wood fires and coal-driven power stations is not only a scourge for the climate but also for human health. Every time we breathe, we inhale these tiny particles in the atmosphere.

Now researchers have for the first time shown that more than half of all inhaled soot particles gets stuck in the lungs. The figure is higher than for most other types of particles. For example “only” 20 per cent of another type of particle from wood smoke and other biomass combustion gets stuck in the lungs.

One explanation is that diesel soot is made up of smaller particles and can therefore penetrate deeper into the lungs, where it is deposited. The study was made on diesel particles (which mainly consist of soot). Ten healthy people volunteered for the study.

“Findings of this kind can be extremely useful both for researchers to determine what doses of soot we get into our lungs out of the amount we are exposed to, and to enable public authorities to establish well-founded limits for soot particles in outdoor air,” said Jenny Rissler, researcher in aerosol technology at Lund University’s Faculty of Engineering and responsible for publishing the study.

In population studies, other researchers have been able to observe that people who live in areas with high concentrations of particulates are more affected by both respiratory and cardiovascular diseases. But since there is no conclusive evidence that it is precisely the soot that is to blame, the authorities have so far not taken any decisions on guidelines.

“Currently there is no specific limit for soot particles in the air, despite the fact that soot in the air is linked to both lung cancer and other diseases,” noted Rissler.

But she thinks that in the future, limits on soot levels will also be set, with reference to the WHO’s recent reclassification of diesel exhaust from “probably carcinogenic” to “carcinogenic”.

Soot particles are not only connected to effects on health but may also contribute to a warmer climate. Paradoxically, other types of aerosol particles can partly be desirable, insofar as they have a cooling effect on the climate and thereby mitigate the warming effect of carbon dioxide.

“Soot particles are black and absorbs light, thus producing a warming effect. So it could be a double advantage to reduce it,” she stated.

Rissler will next be studying individual variations in lung deposition and exposing cells to soot. She is also in the process of further developing methods to measure the surface area of the particles, as this has shown to be an important indicator of their harmfulness.

The study was recently published in the Journal of Aerosol Science.

Source: www.dnaindia.com

06.07.2012

Remember that your own resolution to succeed is more important than any other

Abraham Lincoln