Archive for the ‘risk analysis’ Category
| Newer Entries »Ecosystem stewardship: sustainability strategies for a rapidly changing planet
Saturday, December 12th, 2009
That’s the title of a new article1,2 by Terry Chapin and colleagues in a forthcoming issue of Trends in Ecology and Evolution.
Human actions are having large and accelerating effects on the climate, environment and ecosystems of the Earth, thereby degrading many ecosystem services. This unsustainable trajectory demands a dramatic change in human relationships with the environment and life-support system of the planet. Here, we address recent developments in thinking about the sustainable use of ecosystems and resources by society in the context of rapid and frequently abrupt change.
To deal with these challenges, they advocate “ecosystem stewardship,” which has three core principles. Here are excerpts of these principles (slightly condensed/adapted by me); please check out the paper for details:
Posted in climate adaptation, nature and culture, policy, risk analysis, solutions, sustainable development | No Comments »
When the levees break, we’ll have a more sustainable landscape again
Thursday, December 10th, 2009
We don’t ordinarily think about climate change and land use change as being a synergistic threat to society. However, the combination of impervious surfaces that increase runoff, declining wetlands, levees, and more severe storms pack a quadruple whammy that could lead to some major flooding in the future. From the cool adaptation work done in Keene, NH, we know that much of our infrastructure (roads, bridges, culverts) can’t handle the added stress of streams and rivers with higher discharge. We’re looking at a potential nightmare of increased costs associated with infrastructure damage.
In this week’s issue of Science, Jeffrey Opperman and colleagues argue1 that our historical paradigm of flood control with levees needs to fundamentally change to achieve a more sustainable socioecological system.
Their solution? Tear down some of the levees to allow some floodplains to flood. This can accomplish several goals:
(1) Flood risk reduction
- Move to flood-tolerant activities in floodplains so that we don’t have to spend so much on disaster relief.
- Storing water in floodplains takes the strain off downstream regions because floodwaters can naturally spill to where they are supposed to rather than swelling channelized rivers. Small amounts of land can accomplish this—they cite a study of the Illinois River showing that a floodplain of 8,000 hectares would drop the likelihood of flooding 26,000 hectares of cropland by 50%.
(2) Increased floodplain goods and services
- Several economic activities are conducive to periodic flooding: pasture, timber, and flood-tolerant biofuel crops, such as willow.
- Periodically flooded soils can also assist with reducing erosion and storing nutrients that would otherwise reach and pollute coastal oceans.
(3) Building resiliency to climate change
- They argue that reconnecting rivers to floodplains can help us adapt to climate change in ways that are socioeconomically beneficial. For instance, we presently have to keep some reservoirs partially empty to accommodate periodic flood waters. But partially filled reservoirs can’t generate as much hydropower or provide as much drinking water. If we used floodplains as a natural pressure relief valve, we can operate reservoirs closer to capacity and benefit economically.
Opperman and colleagues acknowledge that there are political hurdles, such as convincing some private landowners that flooding their land can be useful.
But there are creative solutions that have already been deployed. They cite Sacramento as an example: Some farmers allow their crops to flood, serving as a pressure-relief valve when rivers swell, thereby preventing more expensive damage. In return, the farmers are compensated for their crop loss. It’s a win-win situation that presumably costs less than dealing with infrastructure damage or having to build new infrastructure that handles greater flooding.
Another idea is to allow some of these areas to become wetlands and compensate people as part of a wetlands banking system to mitigate the loss of wetlands elsewhere. This would most likely have several ecological benefits, including increasing habitat for wetland-dependent species such as waterfowl and other migrating birds. It would also likely increase vegetation productivity and carbon storage.
It’s interesting to note that they don’t call for an end to economic activity or human use in floodplains. Sure, we probably want to stop building McMansions in flood-prone regions. However, there are several ways we can use floodplains for ecological and economic benefit. These will likely require compensation, but in the long run, it’s cheaper than having to re-tool major infrastructure to handle greater discharge with climate warming.
1Opperman, J.J. et al (2009) Sustainable floodplains through large-scale reconnections to rivers. Science 326:1487-1488.
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Photo credit: http://www.flickr.com/photos/doblonaut/ / CC BY-NC-SA 2.0
Posted in biodiversity science, climate adaptation, food and agriculture, risk analysis, solutions, sustainable development | No Comments »
Are nanoparticles in consumer products increasing your cancer risk?
Tuesday, November 17th, 2009
The field of nanotechnology is exploding, and many materials, such as titanium (Ti), are being shrunk and used in consumer products like sun tan lotions, cosmetics, and toothpaste.
It has been traditionally thought that inert materials like Ti won’t cause health issues because they don’t react with molecules in our cells. New research from UCLA’s Jonsson Comprehensive Cancer Center published in Cancer Research suggests that this conventional wisdom may be flawed.
Ti appears to migrate throughout the body, causing DNA/chromosome breakage and inflammation (both of which are linked to cancer) and oxidative stress causing cell death. Rather than chemically reacting with molecules in cells, the high surface area of the tiny particles appears to cause cell molecules to change.
The manufacture of TiO2 nanoparticles is a huge industry, Schiestl said, with production at about two million tons per year. In addition to paint, cosmetics, sunscreen and vitamins, the nanoparticles can be found in toothpaste, food colorants, nutritional supplements and hundreds of other personal care products.
Once in the system, the TiO2 nanoparticles accumulate in different organs because the body has no way to eliminate them. And because they are so small, they can go everywhere in the body, even through cells, and may interfere with sub-cellular mechanisms.
Photo credit: http://www.flickr.com/photos/29487767@N02/ / CC BY-NC-SA 2.0
Posted in pollutants, risk analysis, technology, toxics | No Comments »
How do women respond to household chemical exposure?
Sunday, November 15th, 2009
Every day, we are exposed to a cocktail of synthetic chemicals from consumer products. How harmful are these? In an earlier post, I described how risk analysis is an important scientific process for determining exposure, effects, and overall risk of these chemicals.
One thing missing from these analyses is how people respond to information about their chemical exposure. In a recent issue1 of the Journal of Health and Social Behavior, Rebecca Altman and colleagues addressed this by analyzing what they call the “exposure experience” of women in Cape Cod, MA—an area with elevated breast cancer rates.
What did they find?
Posted in gender, pollutants, risk analysis, toxics | 2 Comments »
Do our daily routines put our health at risk?
Wednesday, October 14th, 2009
Every day, we are exposed to synthetic chemicals and radiation from consumer products. If you asked me how risky these products are, my responses might range from “I don’t know” to “I don’t want to know” to “If they’re on the market, let’s hope they’re safe!” Unfortunately, it’s difficult to know if many of the things we use every day really are safe.
Risk analysis is a four-step process by which scientists determine whether chemicals or other agents are unhealthy:
- Step 1: Hazard screening–Does a chemical look or act like other chemicals already known to be harmful or safe?
- Step 2: Exposure characterization–How much are we exposed to and how much accumulates in our bodies?
- Step 3: Effects characterization–How do different doses of an agent lead to different health effects, or what we commonly refer to as “dose-response curves”? This is usually achieved using short-term lab animal tests or epidemiological data that show things like health effects of people working at industry sites or living in contaminated neighborhoods.
- Step 4: Risk characterization–Given that we identify a chemical as being potentially dangerous (Step 1), and can measure our exposure (Step 2) and the effects that this specific exposure has on health (Step 3), what is the likelihood or risk that we will experience ill health as a result of the exposure?
As the EPA will tell you, there is often poor understanding of the long term risks of synthetic chemicals and radiation. Much of this comes from the fact that
- We have not screened many of the chemicals on the market for potential safety. Here’s a quote from the EPA’s website in 1996, which was subsequently removed:
For the majority of the approximately 3,000 high production volume industrial chemicals produced in the United States in 1996, we have little or no publicly available hazard screening data. These chemicals, non-polymers produced in quantities of more than one million pounds per year, are found in the workplace and in thousands of consumer products. Even fewer data are available for the remainder of the some 70,000 chemicals on the EPA’s inventory.
- Rigorous effects characterizations are hard to do. Lab animal tests (rats, mice, etc.) are useful, but they are not a perfect substitute for understanding human health impacts. Moreover, the kinds of long-term data we need rarely exist because that’s the nature of short grant funding cycles. We know very little about the synergistic effects of multiple chemicals interacting in our bodies. Finally, health problems analyzed in epidemiological studies can often be confounded with other lifestyle issues, such as weight, diet, exercise, and smoking.
Thus, we know we are exposed to these things, and we can even measure them in our bodies and in infants, but we don’t know very well how this translates to long term health risk.
To some, this uncertainty might be license to ignore the issue. To others, it necessitates better education about what’s in or emanating from our products so that we can decide for ourselves whether or not to limit exposure.
The Environmental Working Group has compiled several interesting lists of consumer products including specific ingredients that have the potential to be harmful:
- Shopper’s guide to pesticides in food
- Shopper’s guide to cosmetics and health care products
- Shopper’s guide to sunscreens
- Shopper’s guide to cell phone radiation
So go ahead and check out your favorite vegetable, shampoo, cell phone, or toothpaste, and see what comes up.
photo credit: http://www.flickr.com/photos/w610guy/ / CC BY-NC-ND 2.0
Tags: chemical, cosmetics, pollutant, radiation
Posted in environmental science, pollutants, risk analysis, shopping guides, toxics | 4 Comments »
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