Environmental Working Group (EWG) has updated their information on cell phone radiation and potential health risks.

As I alluded to in a previous post, conducting human health risk analyses for things like cell phone radiation exposure is difficult because it’s hard to determine how much exposure is too much, and it takes years to see what health effects might show up.

The research below suggests that links between cell phone radiation and health are now becoming evident.

And with more than 4 billion cell phone users worldwide (2/3 of the human population), we are unintentionally conducting one of the largest epidemiological studies of all time.

Learn more from EWG:

• Risks and research—executive summary
• Risks and research—full report (pdf)
• How much radiation does your cell phone emit?
• How to reduce radiation exposure

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• Use political tools to set emissions targets (e.g., 80% reduction by 2050);
• Invest heavily in green technology to drive green energy prices lower.  Only then will these technologies take hold. Carbon reductions are an important byproduct but not the main goal.

Of course these are not mutually exclusive, but they might as well be given the way they have played out on the political stage.

With a lot of people down on political solutions to deal with climate change, strong advocates of the latter approach may now gain the upper hand.  Folks like Shellenberger and Nordhaus have been arguing that green energy needs to be produced as quickly and cheaply as possible—forget all of the games with cap and trade or carbon taxes.   Tom Friedman has also argued the need for swift action on energy, while also endorsing political solutions like carbon taxes.

If you look for areas that are gaining or have the potential to gain traction, there seem to be two levers that may work:

• the link between fossil fuel dependency, climate change, economic stability, and national security;
• the fact that China is eating our lunch with respect to clean energy development.

Both of these general concerns have attracted Republican support for green energy and climate change mitigation, including Senator Lindsey Graham (R-SC).

This may be a signal of potential game changers and the clearest path forward that we’ve seen in awhile.

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Little good news is coming out of Haiti these days.   There’s a deep social-environmental history that needs to be explored to understand why crises like poverty, AIDS, mudslides, and this week’s earthquake have been so devastating to the Haitian people.

I have written a bit about this history for one of the book projects I’m working on.  Below are a few excerpts, but before reading further, please consider helping with the humanitarian relief for earthquake victims:

• Doctors Without Borders USA
• AmeriCares
• An additional list of aid agencies can be found at the NY Times.

When hurricane Jeanne swept across the Caribbean, flooding rains killed over 3,000 people in the small nation of Haiti. Only 18 people died in the Dominican Republic on the same island.  Haiti has one of the highest population densities in the Caribbean. Its 8.7 million inhabitants live on less than half the land occupied by 9.4 million Dominicans, so population density is roughly two times greater.  Puerto Rico’s population density is as high as Haiti’s, but only seven people died in the storm.

Why, if Haiti’s population size is similar to the Dominican Republic’s and population density is the same as Puerto Rico’s, did Haiti suffer such a devastating loss of life?  Some argue that the loss of forests, with their capacity to prevent soil erosion, was a main reason why so many people were killed: heavy rains let loose massive mudslides on deforested hillsides.¹

Deforestation of Haiti’s landscape for agriculture and the manufacture of charcoal have left only 3% of the land surface forested.² Charcoal, produced by cutting trees and slow burning them in mud pits, meets about 85% of energy needs as cooking fuel.³ We see a ravaged countryside today and are tempted to blame this on Haiti’s high population density.  What is not as apparent, however, is how environmental degradation stems from a legacy of colonial resource extraction, slavery, corrupt governments, foreign intervention, and choices about energy, agriculture, and industry.

The mudslides and mortality did not occur in surrounding countries, which have less poverty and deforestation.  In fact, forest area is actually increasing in countries like Puerto Rico and the Dominican Republic where economic growth is rapid. Puerto Rico’s forest cover, for example, has risen from less than 10% to more than 40% in the last 60 years.¹ These forests are recovering on abandoned farmland with the transition from agriculture to industry.

It is therefore too simplistic to blame Haiti’s high population density and consumption of forest resources for the current state of the environment.  Human population growth drives environmental change but is seldom the sole factor behind environmental problems.  Instead, we need to figure out how population changes go hand-in-hand with social, economic, and technological changes so that we can explain environmental impacts.  Understanding and solving environmental challenges often requires simultaneous attention to demographic, economic, political, technological, and cultural values.

Haiti’s indigenous inhabitants practiced subsistence-based agriculture of corn, yams and cassava until their Columbus-era enslavement and genocide. Later, French colonists planted sugar cane in the well-suited warm, wet climate, and developed large, labor-intensive plantations. Throughout the 1700s, France imported thousands of African slaves to Haiti each year such that there were half a million working in 1789. During the colonial period, Haiti’s population was seven times larger than the Dominican Republic’s, which carried forward in time. Haiti exported tens of thousands of tons of sugar and most of the lumber from its forests back to France. The heavy exploitation of land for timber and sugar took a toll on the environment because of widespread land clearing, but it made Haiti one of the most profitable colonies in the Caribbean.

After Haitian independence in the early 19^th century, the nascent government was unable to support its own people in developing cash crops for export. To re-establish trade and diplomatic relations with France, Haiti’s government was forced to pay reparations for land and slaves lost during the revolution.  As much as 80% of Haiti’s budget went to pay these reparations, driving Haiti into significant debt from which it has not yet fully recovered.⁴

Today, Haiti is the poorest country in the Western Hemisphere, with the lowest combination of lifespan, education, and standard of living of any country outside Africa.⁵ Demographic, social, and economic changes happening elsewhere in the Caribbean are not happening as rapidly in Haiti. The abject poverty in which 80% of the population exists deteriorates the country’s environmental and political conditions and constrains economic development.  People are forced to choose between life in urban slums and life as poor, small-scale, subsistence farmers.  More than a million Haitians have emigrated to the United States and elsewhere since 1950.

In recent decades, many Haitian farmers have abandoned agriculture in search of greater profits from supplying charcoal to large urban and rural populations. With the collapse of agricultural and industrial exports, an unemployment rate of 33%, and sliding deeper into poverty, Haitians are forced to destroy remaining forests for charcoal fuel production. Consumption of natural resources just to stay alive is contributing to degraded environmental conditions.

Fertility remains high in Haiti because of high rates of mortality. Maternal, infant, and child mortality rates are high:  Sixty-eight infants and 52 mothers die for every 1,000 live births each year, and the under-five child mortality rate is 123 children per 1,000.  Haiti also suffers from the highest incidence of HIV/AIDS in the Western Hemisphere (5.6% of the population). The leading causes of death are diarrhea, respiratory infections, malaria, tuberculosis, and HIV/AIDS—diseases that are preventable or treatable in more developed countries.  However, 40% of Haitians have no access to health care.⁶ Haiti’s unstable governance, poverty, and environmental degradation exacerbate this need for large families as a social safety net.⁷ This is why simple approaches of reducing fertility, such as government support for contraception, have largely failed in Haiti.

Thus, Haiti’s changes in population and economic welfare, from its subsistence-based land use pattern, to an exploitative resource-extraction system, to a poor society where wealth, industry, and commercial agriculture have pulled out of the country, are not characteristic of the economic pattern—in which increasing economic development begets increased welfare—experienced by much of the developed world over past centuries.

Haiti is battling not only mudslides and earthquakes, but a colonial legacy that has predisposed its people to one devastating crisis after another.

References and Further Reading:

¹Aide, T.M. and H.R. Grau (2004) Globalization, migration, and Latin American ecosystems. Science 305:1915-1916.

²Kaiser, J. (2004) Wounding Earth’s fragile skin. Science 304:1616-1618.

³Collie, T. (2003) We know that this is destroying the land, but charcoal is what keeps us alive. South Florida Sun-Sentinel

⁴Hallward, P. (2004) Option Zero in Haiti. New Left Review 27:23-47

⁵Diamond, J. (2005) Collapse; How Societies Choose to fail or Succeed. Penguin.

⁶Farmer, P. (2004) Political violence and public health in Haiti. New England Journal of Medicine 350:1483-1486.

⁷de Sherbinin, A. (1996)  Human Security and Fertility: The Case of Haiti. Journal of Environment and Development 5(1):28-45.

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Happy New Year, everyone.  Sorry for the lag in posts, but there wasn’t a lot happening in the news or journals over the past week.

A few years ago, I saw a talk by Thomas Schelling (Nobel laureate in economics) who argued that we need to accelerate the economic development of poor countries so that they are able to cope with climate change.  This analysis is interesting, if not fraught with additional challenges, such as development in a carbon-based energy world hastening the very problem to which these nations are attempting to adapt.

In an article¹ in the Early Edition of the Proceedings of the National Academy of Sciences (open access), Anthony Patt and colleagues argued that the need for assistance by Least Developed Countries (LDCs) is dependent on vulnerability, which, in turn, depends on both exposure to climate change and how socioeconomic factors affect the sensitivity of LDCs to climate change.

To assess this hypothesis, they first examined how deaths caused by disasters (floods, droughts, and storms) varied across the level of development in several LDCs.  They used the UN Human Development Index—HDI, a composite metric of income, education, and life expectancy—as a proxy for development.

Here’s what they found…

As you might expect, they found that deaths declined with increased HDI, but interestingly, the relationship had a peak in the middle, suggesting that as the least-developed countries become more developed, they may actually exacerbate vulnerability to climate change at mid levels of HDI before eventually reducing vulnerability at high levels of HDI.

Next, they focused on Mozambique as a case study.  Using the model of deaths vs. HDI they developed for other countries, they projected how Mozambique’s HDI might change over the next 50 years.  To do this, they linked the HDI to different development scenarios outlined by the IPCC’s Special Report on Emissions Scenarios (SRES):

The A2 storyline describes high population and economic growth but low globalization, whereas the B1 storyline describes greater globalization
tied to improvements in environmental quality and sustainability, as well as lower population growth.

Under both scenarios, carbon increases in the atmosphere, but at different rates and to different degrees.  The authors assumed a linear increase in storms/disasters with rising temperatures, indicating that greater warming in the A2 scenario will lead to more disasters and more potential death than the B1 scenario where warming is not as great.

Following the B1 scenario caused the HDI to rise more quickly than the A1 scenario.  Simply put, society on a more-sustainable path (B1) leads to higher social welfare than under a more fossil-fuel intensive path with higher levels of human population (A2).

Similar to what they found by examining many countries, Mozambique will become more vulnerable to increased deaths as HDI rises over coming decades (by 2030-2040).  However, after 2050, vulnerability declined significantly in the B1 scenario, less so in the A2 scenario.

A few excerpts of their conclusions:

The results suggest that vulnerability may rise faster in the next two decades than in the three decades thereafter. Importantly, the overall need for adaptation measures will continue to rise… However,
assuming that their development paths fall somewhere close to the range bounded by the A2 and B1 scenarios, by the second quarter of the century LDCs will likely engage in a greater share of this adaptation autonomously, thereby reducing both their losses, and their need for financial assistance. This is especially the case if socio-economic conditions change in a manner close to that described in the B1 scenario.

….Looking beyond 2060 and the crossing of temperature thresholds such as 2 °C, it may well be that steadily rising climate impacts—such as sea level rise or the effects of cumulative changes on ecosystems—create problems that go well beyond the ability of any country, rich or poor, to adapt. Until that point, a primary argument for ramping up assistance slowly—namely, that adaptation needs can only increase as climate change continues—is incomplete, because it ignores the role that socio-economic development and the concurrent changes in adaptive capacity will have to play. Although there are important caveats to our results, they provide a first estimate of how vulnerability will unfold over the next 50 years, if one assumes, as do all of the SRES scenarios, that
incomes will continue to rise. They suggest that the urgency of efforts to reduce vulnerability, including the provision of international financial assistance, is high.

One thing the authors acknowledge is that nobody really has a good explanation for the humped relationship of HDI vs. deaths from disasters.  That’s an important part of their results, which suggests that the very poorest nations may experience more suffering in the initial steps of development.  Understanding this would make a great PhD in development economics.

¹Patt, A. et al. (in press) Estimating least-developed countries’ vulnerability to climate-related extreme events over the next 50 years. Proceedings of the National Academy of Sciences.

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One of the outcomes of climate warming is that species will have to move to remain within climatic zones that match their physiological tolerances.  Some common examples include the northward migration of boreal forest species into areas that are currently tundra and the upward migration of mountain species.

As Scott Loarie and colleagues note¹ in this week’s Nature (subscription required), we often think of mountain ecosystems as being particularly threatened because alpine species have nowhere to go.

To analyze this challenge, they looked at the spatial gradients of temperature across land masses of the world.  These data indicate how temperature changes over a known distance (temperature gradient = degrees C per kilometer).

Then, they used climate model model projections to determine how fast the temperature of a region will change (warming rate = degrees C per year).

By dividing the warming rate by the temperature gradient, they determined what they called the temperature velocity (kilometers per year)—which is basically represents how fast you (or another species) needs to move along the earth’s surface to maintain a constant temperature (check this division for yourself to see how the units cancel).

What did they find?

Here is the rank order of temperature velocities for biome types (from lowest to highest, with average velocity—km/yr— in parentheses)

• tropical and subtropical coniferous forests (0.08)
• temperate coniferous forests (0.11)
• montane grasslands and shrublands (0.11)
• Mediterranean forests, woodlands, and scrub (0.26)
• tundra (0.29)
• tropical and subtropical moist broadleaf forests (0.33)
• temperate broadleaf and mixed forests (0.35)
• tropical and subtropical dry broadleaf forests (0.42)
• boreal forest (0.43)
• temperate grasslands, savannas, and shrublands (0.59)
• tropical and subtropical grasslands, savannas, and shrublands (0.67)
• deserts and xeric shrublands (0.71)
• mangroves (0.95)
• flooded grasslands and savannas (1.26)

These data suggest that species in the latter categories will have to move much faster than those in former categories to keep up with climate change.

This make sense if you think about it because mountains have steep climate gradients where there is a lot of temperature change over little distance.  We can therefore say that these kinds of habitats have a bit of a buffer against climate warming—indeed, in most of these regions, species only have to be able to move 0.11 km/yr—about the length of a football field.  This runs counter to what most people have thought about mountain ecosystems being especially fragile to climate change.

However, when you look at globally conserved areas, the picture is less rosy.  The authors claim that only 8% of conservation areas have residence times greater than 100 years, meaning that existing climate will be gone in that time.  Put another way, in 92% of conservation areas, climate will be uncharacteristic of the region in less than a century.

This makes conservation extremely challenging—it means that the traditional notions of park boundaries no longer work because species will likely need to move by the end of the century.

There are a few important caveats that the authors point out.  One big one is that the fate of species depends on their breadth of physiological tolerance.  Species with the capacity to tolerate a wide range of climates will not need to move as rapidly (if at all) compared to those with narrow physiological tolerances.

This is an interesting way to show how fast the climate space will move over time, allowing biologists to work more on physiological tolerances to see what species or ecosystem types might be most vulnerable to warming and to develop adaptation plans for them.

¹Loarie, S. et al. (2009) The velocity of climate change. Nature 462: 1052-1057.

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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:

(Principle 1) Reduce vulnerability to known stresses

(A) Reduce exposure to hazards and stresses
• Minimize known stresses and avoid or minimize novel hazards and stresses
• Develop new institutions that minimize global-scale stresses
• Manage in the context of projected changes rather than in the historical range of variability

(B) Reduce social–ecological sensitivities and adapt to adverse impacts
• Sustain the capacity of ecosystems to provide multiple ecosystem services
• Sustain and enhance crucial components of well-being, particularly of vulnerable segments of society
• Plan sustainable development to address the tradeoffs among costs and benefits for ecosystems, multiple segments of today’s society and future generations

(Principle 2) Develop stewardship strategies to prepare for, and shape, uncertain change

(A) Maintain a diversity of options
• Subsidize innovations that foster socio-economic novelty and diversity
• Renew the functional diversity of degraded systems
• Prioritize conservation of biodiversity hotspots and pathways that enable species to adjust to rapid environmental change
• Sustain a diversity of cultures, languages and knowledge systems that provide multiple approaches to meeting societal goals.

(B) Enhance social learning to facilitate adaptation
• Broaden the problem definition and knowledge co-production by engaging multiple disciplinary perspectives and knowledge systems
• Use scenarios and simulations to explore consequences of alternative policy options
• Develop transparent information systems and mapping tools that contribute to developing trust among decision-makers and stakeholders, and build support for action
• Test understanding through comparative analysis, experimentation and adaptive management
• Exercise extreme caution in experiments that perturb a system larger than the jurisdiction of management

(C) Adapt governance to implement potential solutions
• Provide an environment for leadership and respect to develop
• Foster social networking that builds trust and bridges communication and accountability among existing organizations
• Enable sufficient overlap in responsibility among organizations to allow redundancy in policy implementation

(Principle 3) Transform from traps to potentially more favorable trajectories

(A) Preparing for transformation
• Engage stakeholders to identify dysfunctional states and raise awareness of problems
• Identify thresholds, plausible alternative states, pathways and triggers
• Identify the barriers to change, potential change agents and strategies to overcome barriers

(B) Navigating the transition
• Identify potential crises and use them as opportunities to initiate change
• Maintain flexible strategies and transparency
• Foster institutions that facilitate cross-scale and cross-organizational interactions and stakeholder participation

(C) Building resilience of the new regime
• Create incentives and foster values for stewardship in the new context
• Initiate and mobilize social networks of key individuals for problem solving
• Foster interactions and support of decision makers at other levels

Bottom line:  This paper provides a useful framework for the continuing conversation on sustainability.  Some of the ideas are not new, but it’s a good synthesis, and it makes progress towards the difficult task of integrating natural and social systems. I would like to see a comprehensive list of examples compiled for all of these strategies as a clearinghouse for ideas, including ideas that do (did) not work.

We are going to see a lot more on these ideas over the next decade:

• interdependence of natural and social systems
• reducing vulnerabilities (a key component of adaptation)
• fostering innovation in all sectors of society
• maintain diversity in ecological and social systems as a form of resilience (another key component of adaptation)
• being proactive to shape the trajectory of change

¹Chapin F.S. et al (in press) Ecosystem stewardship: sustainability strategies for a rapidly changing planet. Trends in Ecology and Evolution

²Bowdoin people can access the article here.

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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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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

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?

As part of a larger analysis (Silent Spring Institute’s Household Exposure Study), they measured 120 homes for 89 chemicals that could affect hormones.  They also measured blood and urine concentrations in a sample of female residents.

They found that after receiving the chemical concentration data about their homes, participants concluded one or more of the following statements:

• Synthetic chemicals can be detected in household air and dust, and in human samples such as urine (e.g., “There’s chemicals everywhere in this place!”)
• Most homes have chemicals.
• Homes contain a variety of different chemical compounds.
• Even banned substances, such as the pesticide DDT, were detected.
• There are numerous sources for chemicals found in urine, blood, and household air and dust.
• Many common, household sources of chemical exposures are unregulated or understudied.

The response of many of the women included follow-up questions like

• Do these results signal a problem?
• What is “acceptable”?
• Where are these chemicals coming from?
• And, what should I do?

Altman and colleagues argued

In response to these circumstances, study participants reached out to others. As indicated in the previous excerpt, participants contacted the scientists, but they also queried friends and family (e.g., a friend with cancer, a daughter with a medical degree, or a son with scientific training). They shared study results with their physicians or oncologists. Some participants consulted Internet resources or local libraries. One participant copied the results for her landscaper, who had applied pesticides to her lawn and garden. Yet, as these participants reported, their friends and contacts—including their physicians—had few new insights to offer. Left unresolved were lingering questions: Participants’ narratives reflected puzzlement over how to interpret levels and make appropriate responses.

The research team noted that the participants were surprised by the number of chemicals detected in air and dust, and they weren’t sure where they could come from because the women perceived themselves using few chemicals.  It turns out, as Altman’s team discovered, they were actually using several products containing these chemical, illustrating the disconnect between consumer culture an its associated chemical exposure risks.

Another trend:  One of the first reactions of the participants was to attribute chemical levels to historical uses in the home, often citing the age of the home.  But, again, this reflects the tendency to look for explanations beyond current consumption patterns.

They also found that participants may have underestimated the threat of chemical concentrations in their homes.  When examining a graph showing the chemical concentrations in their home relative to all other participants’ homes and the EPA guideline level, many participants shrugged off their results as “average” when their home fell in the middle of the data values even when all of the data were above the EPA safety guideline.  As Altman noted,

[f]or most participants, this perception of “average-ness” allayed concerns of health risk.

When the participants were concerned about the levels of chemicals in their homes, Altman argued that they sometimes fell victim to bad mental models of what to do:

• technological fallacy—that it’s simply a matter of cleaning them up
• consumption fallacy—that it’s simply a matter of switching products, when in reality (1) it’s often not clear how to do this, (2) there may be no good alternatives for certain products, or (3) switching may do no good.   When one woman learned that she had pesticides in her urine, despite eliminating them from her home and eating organically, she was understandably shocked:
  It was overwhelming to know how many chemicals they found in my house, especially like I’ve already said, I’ve made really conscious efforts to eliminate so many things [pesticides]—my lawn, everything on the food that I eat. I have a water filtration system that cost me a thousand dollars to, you know, to purify my water. I’ve made so many, many little things like that … and to know that even so many years after my diagnosis, to know that I’m still being exposed. It’s overwhelming.

Interestingly, when confronted with the notion that chemical levels remained high even after efforts to reduce them, several of the participants began controlling them symbolically, for example, by dissociating pesticides sprayed in the neighborhood with those found in their homes or bodies.

Bottom line:

One of the conclusions that Altman draws is that scientists conducting risk analyses need to think about the context/starting assumptions that people have regarding scientific exposure data.  Specifically, it’s not enough for scientists to think about how to present uncertainty in the data; they also need to understand the “unique social and historical setting” in which the data are interpreted.

These stories make a compelling case that sociologists are (should be) an important part of the risk analysis process.

Related post: Do our daily routines put our health at risk?

¹Altman, R. (2008) Pollution comes home and gets personal: Women’s experience of household chemical exposure. Journal of Health and Social Behavior 49(4): 417-435.

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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