by Karen Foster,
As a species, we’re just beginning to recognize that the environment is vital to our health. The need to reduce acid rain emissions, stop dumping hazardous wastes, and slow down deforestation needs be addressed from the perspective of people’s health. Evidence is increasing from multiple scientific fields that exposure to the natural environment can improve human health.
The health of our environment affects human health in different forms. The air we breathe, the water we drink and the food we eat are quickly becoming polluted to the point of being unsafe to consume without endangering our well-being. Will there be a point of reversal?
For Geoffrey Donovan, a research forester at the Forest Service’s Pacific Northwest Research Station, and his colleagues, the loss of 100 million trees in the eastern and midwestern United States was an unprecedented opportunity to study the impact of a major change in the natural environment on human health.
In an analysis of 18 years of data from 1,296 counties in 15 states, researchers found that Americans living in areas infested by the emerald ash borer, a beetle that kills ash trees, suffered from an additional 15,000 deaths from cardiovascular disease and 6,000 more deaths from lower respiratory disease when compared to uninfected areas. When emerald ash borer comes into a community, city streets lined with ash trees become treeless.
The researchers analyzed demographic, human mortality, and forest health data at the county level between 1990 and 2007. The data came from counties in states with at least one confirmed case of the emerald ash borer in 2010. The findings — which hold true after accounting for the influence of demographic differences, like income, race, and education — are published in the current issue of the American Journal of Preventive Medicine.
” There’s a natural tendency to see our findings and conclude that, surely, the higher mortality rates are because of some confounding variable, like income or education, and not the loss of trees,” said Donovan. “But we saw the same pattern repeated over and over in counties with very different demographic makeups.”
Although the study shows the association between loss of trees and human mortality from cardiovascular and lower respiratory disease, it did not prove a causal link. The reason for the association is yet to be determined.
We can longer neglect the mounting evidence of wasteful and destructive human activities which are undermining the capacity of our planet to provide a secure and hospitable home for all its peoples, both rich and poor.
Human activities have created a technological civilization that is now global in scale and pervasive in its influence on the lives and the prospects of all members of the world community. It has produced a world with stark dichotomies between the benefits enjoyed by the few, and the deprivation and suffering experienced by the majority. The gross imbalances created by the concentration of economic growth in developed nations and the high rates of population growth in developing countries are at the centre of the current dilemma.
It’s time we realized that our entire world is a reflection of our health and our interactions with each other. If we refuse to nurture our environment and care for our own planet, what does that say about how we think of ourselves?
Karen Foster is a holistic nutritionist, avid blogger, with five kids and an active lifestyle that keeps her in pursuit of the healthiest path towards a life of balance.
Read more at: Prevent Disease
[msa-ads data-ad-client=”ca-pub-6965588547261395″ data-ad-slot=”7732882042″]
Tuesday, November 20, 2012
Credit: Nina Jenkins A bed bug with Beauveria bassiana sporulating on its cadaver.
UNIVERSITY PARK, Pa. – “And don’t let the bedbugs bite” is no longer a harmless adage. In reality today, these bloodthirsty bugs infest thousands of homes. According to a team of Penn State entomologists, biopesticides — naturally occurring microorganisms — might provide an answer to this pest problem.
Bedbugs need blood meals for growth and development throughout their life cycle. Increased travel, widespread insecticide resistance and changes in management practices have caused a resurgence in those insects throughout North America and Europe. Compounding the problem are concerns about the safety of using traditional chemicals in the domestic environment.
According to Nina Jenkins, senior research associate in entomology, preliminary bioassays on the effects of Beauveria bassiana — a natural fungus that causes disease in insects — on bedbug control have been performed, and the results are encouraging. She and her colleagues report their results in the most recent issue of the Journal of Invertebrate Pathology.
Jenkins, working with Alexis Barbarin, a former Penn State postgraduate student now at the University of Pennsylvania, Edwin Rajotte, professor of entomology, and Matthew Thomas, professor of entomology, looked at how B. bassiana acts through contact with its insect host.
“They are natural diseases that exist in the environment,” said Jenkins. “They are relatively easy to produce in a lab and stable, so you can use them much like chemical pesticides.”
In the study, the researchers used an airbrush sprayer to apply spore formulations to paper and cotton jersey, a common bed sheet material. Then control surfaces, again paper and cotton jersey, were sprayed with blank oil only. The surfaces were allowed to dry at room temperature overnight. Three groups of 10 bedbugs were then exposed to one of the two surfaces for one hour. Afterward, they were placed on clean filter paper in a petri dish and monitored.
The researchers found that all of the bedbugs exposed to the biopesticide became infected and died within five days.
Also, there were no prominent differences in susceptibility by feeding status, sex, strain or life stage. Most importantly, the infected bedbugs carried the biopesticide back to their hiding places, infecting those that did not go out in search of blood.
“We exposed half of a population of bedbugs to a spray residue for one hour and then allowed them to go into a harborage with unexposed individuals,” said Jenkins. “The fungal spores were transferred from the exposed bug to their unexposed companions, and we observed almost a hundred percent infection. So they don’t even need to be directly exposed, and that’s something chemicals cannot do.”
This result is important because bedbugs live in hard-to-reach places.
“Bedbugs tend to be cryptic, and they’ll hide in the tiniest crevices,” said Jenkins. “They don’t just live in your bed. They hide behind light switches and power sockets and in between the cracks of the baseboard and underneath your carpet.”
The speed of mortality with B. bassiana is as fast as Jenkins has seen in any application, but it doesn’t even need to be that fast.
“If you are trying to protect a farmer’s field, he wants the insects that are eating his crop dead immediately,” said Jenkins. “Obviously, if you have bedbugs in your house, you don’t want them there for any longer than you have to, but what you really want to know is if they’ve all gone at the end of the treatment, and I think that’s something that this technology could offer.”
Next, the researchers will test the effectiveness of brief exposure times and look at entire populations where natural harborages are established. Then they will begin field work.
“It’s exciting, and it definitely works,” said Jenkins. “We’re working on the next step, and we have more funding to support these studies.”
Editors note: Full article can be found here.