Showing posts with label chemical exposure. Show all posts
Showing posts with label chemical exposure. Show all posts

Friday, December 24, 2010

'Twas the Night Before Christmas

It's a favorite story to be read in so many households tonight, but this version is for all the science lovers out there. I can't take the credit for this beautiful rendition of Chemistry Christmas by Matt Monroe.

'Twas the night before Christmas,
The lab was quite still;
Not a Bunsen was burning
(Nor had they the will).
The test tubes were placed
In their racks with great care,
In hopes Father Chemistry
Soon would be there.

The students were sleeping
So sound in their dorms,
All dreaming of fluids
And Crystalline forms.
Lab-Aids in their aprons
And I in my smock.

When outside the lab
There arose such a roar
I leaped from my stool
And fell flat on the floor.
Out of the fire escape
All of us flew.
What was the commotion?
Not one of knew.

The flood-lights shone out
O're the campus so bright
It looked like old Stockholm
On Nobel Prize Night.
My fume-blinded eyes
Then viewed (dare I say?)
Eight anions pulling
A water-trough sleigh.

And holding the bonds
Tied to each one of them
Was a figure I knew
As our own Papa Chem.
With speeds in excess
Of most X-rays they came.
As they Dopplered along
He called each one by name.

"Now Nitrite, now Phosphate,
Now Borate, now Chloride
On Citrate, on Bromate,
On Sulfite and Oxide.

Forget what you know
Of that randomness stuff,
Let's go straight to that roof,
If you've quanta enough."

As fluids Bernoullian
Behave in a pinch,
Those ions said "Alchemist
This is a cinch."
So up to the lab-roof
Those "chargers" they sped
With Pop Chemistry safe
In his water-trough sled.

Just a microsec later
Electroscopes showed
Charged particles coming
To our lab abode
We raced back inside,
And what d'ya think?
Down the fume-hood Pop Chem fell,
Right into the sink.

He was dressed in a lab-coat,
Quite ragged and old,
With removable buttons
(The style, we're told)
A tray-full of beakers
He clutched to his heart--
And under his arm
Was an orbital chart.

His eyes through his goggles
I just couldn't see
His hands were all yellow
From H-N-O-3.
His head was quite bald
With a fringe all around
Like a ring test for iron,
That same shade of brown.

He puffed a cigar
With a smell not at all
Unlike the organic lab
Right down the hall.
The smoke billowed forth
From his angular face
And with Brownian Movement
Enveloped the place.

He was thin as a match
And not terribly tall
He wasn't the type
I'd expected at all
But a look at his clothes,
In the lab's harsh white light,
With their acid-burn holes--
He's a chemist all right!

He didn't say much
(He had no time to kill)
And filled all the test tubes
With nary a spill.
Then placing them bak
On the benches with care
He dashed to the fume-hood
And rose through the air.

He called to his team
And his ions took off
And kinetics took care
Of Pop Chem and his trough,
But I heard him cry out
As he flew down the street
"Merry Holidays to all!
May your stockrooms stay neat!"


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Wednesday, May 26, 2010

Call to Action

Image credit: A6U571N

The bottom line is that environmental chemicals, such as endocrine disrupting chemicals, are a real concern, but the specific health threats are still poorly understood. Environmental health research is key to improving public health, because it will help us determine how we can prevent rather than treat environmentally related effects.

The ultimate outcome of this research will be information that can be used to guide policy by identify chemicals of concern, determine exposure levels that lead to health effects, and evaluate the effectiveness of prevention efforts. But beyond policy, this data will allow people to make better choices, such as where to live or types of health care they need.

Investment in environmental health research clearly has the potential to improve Americans quality of life and reduce economic and societal costs that result from environmentally-related health effects. As voters, we have the power to encourage investment in this research by telling the representatives we elected that it is how we want our tax dollars spent. The greatest impact you can have is by communicating with your representatives.

I am writing letters to my Senators and Representatives on how I believe environmental health research should be a priority, will you join me?


This is Part 10 in the Chemical Exposures and Public Health series.
Part 1 - From Interest to Passion
Part 2 - An Environmental Health Risk
Part 3 - Lead: A Regulatory Success Story
Part 4 - Something My Body Needs Anyway?
Part 5 - Obesity's Elephant: Environmental Chemicals
Part 6 - Why Our Approach to Toxicology Must Change
Part 7 - Failures of U.S. Chemical Regulation
Part 8 - Cleaning Up Our Act
Part 9 - Environmental Health Research Saves Lives and Money
Part 10 - Call to Action

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Monday, May 24, 2010

Environmental Health Research Saves Lives and Money

Along with public opinion and advocacy, research is another important driver of policy decisions. Research is the an essential tool for the identification of safe alternatives for chemicals in commerce that are a health concern. Efforts by scientists in areas such as green chemistry aim to design new chemicals that have little to no negative effects on our health.

The same research tools can also be used to guide chemical regulatory policy. To encourage regulation of a specific chemical, research needs to prove it poses a threat to human health. To better understand the risk posed by chemical exposures, scientists first needed to develop methods to identify which chemicals are getting into our bodies and at what levels. One technique is bio-monitoring; which involves looking at both the environment a person lives in and samples from the person themselves.

Historically, human exposures were estimated from the concentration of a chemical in the environment, food, water, or consumer goods. But advances have enabled scientists to directly measure the concentration of a chemical or metabolites in specimen, such as blood, urine, or bone. A recent CDC study detected over 212 chemicals in the U.S. population. Even DDT was found at a detectable level in children, despite the fact that it had been banned decades before they were born.

But what does bio-monitoring data mean for public health? The problem is that bio-monitoring studies on their own do not determine the relationship between chemical exposures and health effects. Bio-monitoring is the first step, but can only determine what enters our bodies. In order for regulatory action to be taken, these chemical exposures must be linked to specific effects, as was done for children's lead exposure and mental deficits. Unfortunately, for endocrine disrupting chemicals (EDCs) many links remain unknown.


To better determine links between environmental exposures and health effects, a multi-agency collaboration is conducting a national research effort called the National Children’s Study . The study will track 100,000 children from before birth to the age of 21 collecting data on their chemical exposures and potentially related health effects. Then, researchers will analyze the data to learn how environment influences health, including evidence identifying which chemicals in our bodies are making us sick.

The study is focusing on children because research has documented their unique vulnerability to chemicals, and how exposures during development can set us up for chronic health problems and the development of diseases later in life.

Because of the sheer size and length, the National Children’s Study will be expensive. To get the full benefit, it is critical that funding is maintained. This study is about prevention, we need to try to stop environmentally related health effects before they start. Investment in environmental health research is important because of the clear potential to save both lives and treatment costs.


This is Part 9 in the Chemical Exposures and Public Health series.
Part 1 - From Interest to Passion
Part 2 - An Environmental Health Risk
Part 3 - Lead: A Regulatory Success Story
Part 4 - Something My Body Needs Anyway?
Part 5 - Obesity's Elephant: Environmental Chemicals
Part 6 - Why Our Approach to Toxicology Must Change
Part 7 - Failures of U.S. Chemical Regulation
Part 8 - Cleaning Up Our Act
Part 9 - Environmental Health Research Saves Lives and Money
Part 10 - Call to Action

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Thursday, May 20, 2010

Cleaning Up Our Act

Image credit: Method

In my last post, I described some of the legislative hurdles for U.S. chemical regulation. How can Americans encourage positive change? The best ways to influence policy is through public support since legislators respond to their constituents concerns. Advocacy is an effective tool to raise public awareness and is most powerful when backed by research.

A public opinion poll conducted in August 2009 for Safer Chemicals, Health Families showed that Americans are concerned with the way the U.S. currently regulates chemicals. When given a description, 74% say they support the Toxic Substances Control Act (TSCA). 87% expressed concern when they learned that chemicals in existence prior to TSCA were simply presumed safe and grandfathered. And 71% were in support of proposed changes for the legislation.
Image credit: Campaign for Safe Cosmetics

This public support is being generated and maintained by advocacy. Advocates try to educate the public about regulatory issues through books, such as Not Just A Pretty Face by Stacy Malkan, which raises concerns about chemicals in personal care products, and Slow Death by Rubber Ducky by Rick Smith and Bruce Lourie, which examines how everyday items we use are polluting our bodies. Advocates also use advertisements to raise awareness about harmful chemicals in makeup, from the Campaign for Safe Cosmetics, or cleaning products, from Method.

In response to public concern, many companies have already begun to reformulate products, removing specific chemicals without government intervention. Two endocrine disrupting chemicals that have already begun to be phased out are BPA, which is used to make reusable water bottles, baby bottles, and carbonless paper receipts, and phthalates, a group of chemicals used to soften children’s plastic toys and to help fragrances last longer.

However, a specific chemical being removed does not guarantee the new product is any safer. Manufactures simply swap one chemical for another, but just like the initial chemical, the alternatives are not being thoroughly tested for safety. It becomes a game of 'whac-a-mole', with
another concerning chemical popping up every time you knock one down. Regulatory changes are critical so that we don’t have to remove dangerous chemicals from products, but instead are preventing them from getting to the market in the first place.

What's the best way to ensure that the environmental chemicals we are exposed to are safe? Research. Stay tuned for the next part of this series on the benefits of Environmental Health Research.

This is Part 8
in the Chemical Exposures and Public Health series.
Part 1 - From Interest to Passion
Part 2 - An Environmental Health Risk
Part 3 - Lead: A Regulatory Success Story
Part 4 - Something My Body Needs Anyway?
Part 5 - Obesity's Elephant: Environmental Chemicals
Part 6 - Why Our Approach to Toxicology Must Change
Part 7 - Failures of U.S. Chemical Regulation
Part 8 - Cleaning Up Our Act
Part 9 - Environmental Health Research Saves Lives and Money
Part 10 - Call to Action

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Thursday, May 13, 2010

Failures of U.S. Chemical Regulation

Image credit: Echoey13

In previous posts, I've shared how research demonstrates a link between endocrine disrupting chemicals (EDCs) and negative health effects, such as obesity. Since EDC exposures are a health concern, the government needs to identify chemicals of concern and implement policies to reduce exposures, as was done for lead. Unfortunately, U.S. chemical regulation is not a straightforward process.

Chemical regulation is split between several agencies. Two of the main agencies are the U.S. Food and Drug Administration (FDA) and the Environmental Protection Agency (EPA). The FDA oversees chemicals we are exposed to through certain consumer products like pharmaceuticals, cosmetics, and food additives, while the EPA regulates exposures that are more environmental, such as air pollution.

Some authorities are further split, as is the case for water, with bottled water being regulated by the FDA and tap water by the EPA. As a result, individual contaminants could end having different maximum permissible amounts in bottled vs. tap water.

This fragmented regulation makes it difficult to protect public health. But there were also a large number of chemicals in commerce that were initially unregulated if they were not covered under other existing laws, such as the Federal Food, Drug, and Cosmetics Act which regulates pharmaceuticals. In an attempt to close this gap, Congress passed the Toxic Substances Control Act (TSCA) in 1976, which gave EPA the authority over all unregulated chemicals.

A major flaw is that TSCA treats new chemicals differently than chemicals that existed before the act. Existing chemicals were not evaluated and were just presumed safe. At the time TSCA passed, there were already about 62,000 chemicals in commerce. Regulation of new chemicals isn’t much better and has limited requirements. Companies are only required to submit available data and don’t have to test for toxicity. It is estimated that only 15% of new chemicals have complete health and safety data.

TSCA had the potential to unify regulatory authority, by giving the EPA authority over chemicals of unreasonable risk to health or the environment. For example, BPA is approved by the FDA as an indirect food additive, but because of concerns for human health, the EPA is using its authority under TSCA to investigate BPA.

However, the phrase “unreasonable risk” created another major hurdle, because it places the burden of proof on the EPA, and requires a significant level of evidence prior to regulatory action that can take years to develop. As a result, chemicals are only regulated when proven harmful rather than requiring they are proven safe to enter the market.

TSCA was introduced over 30 years ago. Today, there are over 80,000 chemicals approved for use in the products we use, such as household cleaners, shampoo, and makeup. But to date, the EPA has only been able to regulate 5 chemicals and require testing for about 200. I feel the numbers clearly show that TSCA has failed to protect Americans.

Image credit: Abeeeer

The U.S. Government Accountability Office (U.S. GAO), the agency that evaluates the effectiveness of government programs and policies, also believes TSCA has not given the EPA the necessary authority to protect human health and the environment. U.S. GAO put the EPA's process for "assessing and controlling toxic chemicals" on its "high-risk" list in 2009. The list includes federal programs, policies, and operations that should be a top priority for reform

Currently, Congress is considering legislation to reform TSCA. Senator Frank Lautenberg (D-NJ) introduced a bill called the Safe Chemicals Act of 2010 in the Senate. Representatives Bobby Rush (D-IL) and Henry Waxman (D-CA) have released a discussion draft of the Toxic Chemicals Safety Act of 2010 in the House. Only time will tell if these bills will provide Americans with meaningful reform that will improve public health.

This is Part 7 in the Chemical Exposures and Public Health series.
Part 1 - From Interest to Passion
Part 2 - An Environmental Health Risk
Part 3 - Lead: A Regulatory Success Story
Part 4 - Something My Body Needs Anyway?
Part 5 - Obesity's Elephant: Environmental Chemicals
Part 6 - Why Our Approach to Toxicology Must Change
Part 7 - Failures of U.S. Chemical Regulation
Part 8 - Cleaning Up Our Act
Part 9 - Environmental Health Research Saves Lives and Money
Part 10 - Call to Action


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Tuesday, May 11, 2010

Why Our Approach to Toxicology Must Change

Exposures to endocrine disrupting chemicals (EDC) are a particular concern for children. Because children are developing rapidly, hormone disruption can have a greater impact; resulting in chronic health problems or making children susceptible to the development of illnesses later in life.

Research has shown that chemicals in a mother's body are able to cross the placenta, and therefore, children are being exposed to environmental chemicals even while they are in the womb. As infants, they are exposed to chemicals at higher levels because consume more food relative to body weight, but also because their immune systems are less developed, and therefore, less able process and remove chemicals from their bodies.

For lead, proper regulation took several decades because we initially had a poor understanding of its health effects. We face the same problem today with EDCs.

The famous adage the "dose makes the poison" describes the assumption toxicologists use when determining safe chemical exposure levels. Toxicology studies currently assume that a greater dose, or exposure level, will produce a greater effect.

To determine safe exposure levels, animals are exposed to varying amounts of a chemical and a dose that does not produce observable effects is identified. Then, a series of uncertainty factors are applied to that dose in order to calculate an acceptable level for human exposure. The uncertainty factors account for different sensitivities between the animals studied and humans but also to account for varying sensitivities between humans.

So, what is wrong with the current approach?

Scientists who study the endocrine system have recognized for a while that hormones have a different relationship between dose and effect. Hormones and hormone mimicking chemicals, like EDCs, can produce opposite effects at different exposure levels. A low level exposure can turn a process on, while a high level exposure could shut the process off.

Since EDCs have a different dose-effect relationship, the current assumptions used in toxicology studies are outdated. High-dose experiments can not be effectively used to predict low-dose results for EDCs, and therefore, safety testing needs to be adapted to make sure that potential low-dose effects are investigated. In order to address our evolving understanding of endocrine disruption, the Endocrine Disruptor Screening Program was established by the Environmental Protection Agency to develop a battery of tests to properly identify EDCs, information that will enable us to update the way we conduct toxicology studies.

The scientific understanding of how endocrine disruption can be identified and measured is still in the early stages, and research will be our best chance to close these knowledge gaps and identify chemicals that are a real public health threat.


This is Part 6 in the Chemical Exposures and Public Health series.
Part 1 - From Interest to Passion
Part 2 - An Environmental Health Risk
Part 3 - Lead: A Regulatory Success Story
Part 4 - Something My Body Needs Anyway?
Part 5 - Obesity's Elephant: Environmental Chemicals
Part 6 - Why Our Approach to Toxicology Must Change
Part 7 - Failures of U.S. Chemical Regulation
Part 8 - Cleaning Up Our Act
Part 9 - Environmental Health Research Saves Lives and Money
Part 10 - Call to Action


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Monday, May 10, 2010

Obesity's Elephant: Environmental Chemicals

Today, obesity is the fastest rising health concern in the U.S. Obesity is a problem that people have tried to use both diet and exercise to combat, yet a growing body of research is suggesting there is another component of this problem, our exposure to environmental chemicals.

Endocrine disrupting chemicals (EDCs) are a public health concern because they mimic natural hormones and interfere with our endocrine system. Research shows a potential link between children being exposed to EDCs during development and the increased burden of chronic health problems, such as obesity.

One EDC you may have heard about recently is Bisphenol-A (BPA). BPA has been used for years in the production of reusable water bottles and baby bottles, but now many companies are now offering BPA-free products.

The reason BPA is becoming a public health concern is that research has demonstrated a link between children's exposure to BPA during critical developmental windows - such as in the womb or as infants - and obesity. For example, Nikaido et al. exposed pregnant rats to BPA to determine the effects on fetal development [1]. The results showed that prenatal exposure to BPA at human-relevant doses accelerated weight gain of the female offspring compared to offspring of the mothers not exposed to BPA.

This study is one of many that demonstrate chemical exposures could be a factor, changing our bodies in ways that make us obese.


References
1. Nikaido, Y. et al. Reprod. Toxicol. 2004; 18: 803-811.


This is Part 5 in the Chemical Exposures and Public Health series.
Part 1 - From Interest to Passion
Part 2 - An Environmental Health Risk
Part 3 - Lead: A Regulatory Success Story
Part 4 - Something My Body Needs Anyway?
Part 5 - Obesity's Elephant: Environmental Chemicals
Part 6 - Why Our Approach to Toxicology Must Change
Part 7 - Failures of U.S. Chemical Regulation
Part 8 - Cleaning Up Our Act
Part 9 - Environmental Health Research Saves Lives and Money
Part 10 - Call to Action


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Friday, May 7, 2010

Something My Body Needs Anyway?

Image Source: Time Magazine

The impact of environmental chemicals on health is becoming a defining concern of this century. I’m sure you’ve seen the increasing number of articles published by the mainstream media questioning the safety of chemicals in consumer products, like plastics. Research has shown that these chemicals are getting into our bodies and can mimic our hormones.

Hormones are signals that regulate biological processes by communicating messages to cells. Hormones bind to a receptor like a key fits into a specific lock, which tells the cell to carry out a specific action.

One example is human growth hormone. As children, growth hormone is released in our body to tell limbs and organs to grow. But when we become our adult size, our body stops releasing the growth hormone, so the cells are no longer receiving the message to grow. Hormones are regulated by a group of glands called the endocrine system.

Image credit: Principles and Explorations, Teaching Transparencies.
Copyright 1996 by Holt, Rinehart and Winston.

Certain unnatural chemicals entering our bodies can mimic our natural hormones. They are called endocrine disrupting chemicals (or EDC) because of their ability to interfere with our endocrine system.


The problem with EDCs is that they are not made by your body, and therefore, your body is not able to regulate EDCs like it regulates your natural hormones. But at the same time, EDC’s (green) can bind to the receptors (purple) of specific natural hormones (orange), initiating the same cell response. Research suggests that EDCs artificially switching processes on and off and at the wrong time is contributing to the rising burden of illness in America.

I am particularly interested in EDCs because we are just now discovering the sheer number of chemicals that have the ability to act this way, but we don’t yet know which chemicals, or at what exposure levels, are linked to which real public health threats.

The government again needs to decide if regulatory action is necessary, a decision that depends largely on whether the chemicals pose a threat to U.S. health.


This is Part 4 in the Chemical Exposures and Public Health series.
Part 1 - From Interest to Passion
Part 2 - An Environmental Health Risk
Part 3 - Lead: A Regulatory Success Story
Part 4 - Something My Body Needs Anyway?
Part 5 - Obesity's Elephant: Environmental Chemicals
Part 6 - Why Our Approach to Toxicology Must Change
Part 7 - Failures of U.S. Chemical Regulation
Part 8 - Cleaning Up Our Act
Part 9 - Environmental Health Research Saves Lives and Money
Part 10 - Call to Action

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Wednesday, May 5, 2010

Lead: A Regulatory Success Story

Research!America's former chairman, the Honorable Paul G. Rogers recognized that environmental factors played a major role in health effects and was a consistent advocate for changing environmental policy to improve public health. His work to pass the Clean Air Act is actually part of a larger story about how research played a major role in the 20th century guiding policy to successfully regulate lead.

Today, we know that lead exposure is a problem for children’s health, but this wasn’t always the case. Research evolved the scientific understanding of lead poisoning, which can be broken down into four stages [1].
  1. Children assumed not to be affected by lead
  2. Cases of acute lead poisoning were identified but were thought to result in either death or recovery
  3. Lasting mental deficits only occur when children had clinical symptoms of lead poisoning
  4. Children without clinical symptoms can still have mental deficits in language, IQ, or attention
In response to research, the Center for Disease Control and Prevention (CDC) adjusted its definition of a safe blood lead level for children, which prompted regulations to reduce lead exposure.


There were two major sources of lead exposure for children: leaded gasoline and lead paint.

Lead was a standard additive in gasoline, but in 1965, research demonstrated that the increased lead concentrations in the air were the direct result of human activities, like burning leaded gasoline. This clear link between air quality and health was why Paul Rogers led the fight to pass the Clean Air Act. Passage of the Clean Air Act paved the way for the phase-out of lead in gasoline by 1996.

Lead based paints were commonly used in homes in the early 1900s. Research linking lead exposure to children's health effects prompted a 1978 federal limit on the lead content in paints used in residential buildings.


Together, these policy actions were extremely successful at reducing lead exposure. Banning leaded gasoline reduced the average air lead concentration by 94%. This ban, in conjunction with the limit on the lead content in paint, reduced the average blood lead level in children more than 7 times below the 1970s level.

This reduction in the United States is estimated to have resulted in an economic gain between $110 and $319 billion dollars for children born in a given year [2]. This economic gain was calculated using the increased worker productivity that will result from the improved cognitive ability of children with lower lead exposures.

Lead regulation is a great example of how research can lead to policy changes that can benefit public health and save money.


References
1. H. Needleman. Annu. Rev. Med. 2004; 55: 209-222.
2. Grosse, S.D. et al. Environ. Health Perspect. 2002; 110: 563-569.


This is Part 3 of 10 in our Chemical Exposures and Public Health series.
Part 1 - From Interest to Passion
Part 2 - An Environmental Health Risk
Part 3 - Lead: A Regulatory Success Story
Part 4 - Something My Body Needs Anyway?
Part 5 - Obesity's Elephant: Environmental Chemicals
Part 6 - Why Our Approach to Toxicology Must Change
Part 7 - Failures of U.S. Chemical Regulation
Part 8 - Cleaning Up Our Act
Part 9 - Environmental Health Research Saves Lives and Money
Part 10 - Call to Action


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Tuesday, May 4, 2010

An Environmental Health Risk

Feeling The Heat (8396)
Image credit: Echoey13

How often do you think about the chemicals in products you buy and if they could affect your health? We use a number of products every day from shampoo to cleaning products and we expect that the government regulates these products to make sure they are safe.

Unfortunately, in the past, certain chemicals have been discovered to affect our health only after they reached the market, as was the case for lead paint. Today, this is happening again with a group of compounds called endocrine disrupting chemicals, which mimic our hormones.

WWII increased demand for products, resulting in the development new uses for natural chemicals, which exposed us at higher levels, and the acceleration of the production of chemicals not previously found in nature. But no one thought about potential effects on our health, until Rachel Carson published Silent Spring. Her book raised awareness that chemicals could interact with our bodies.

Image credit: Beverly & Pack

Carson published evidence that the pesticide, DDT, had put the bald eagle on a path towards extinction, and if it was hurting wildlife, it could potentially be harmful to humans as well. DDT was considered a miracle pesticide and was used for everything from combating malaria to protecting cotton. However, Carson's book spurred national action that ultimately led to a ban of DDT.

Silent Spring was the beginning of an environmental movement, which I'll share some results of in more detail tomorrow.


This is Part 2 of 10 in our Chemical Exposures and Public Health series.
Part 1 - From Interest to Passion
Part 2 - An Environmental Health Risk
Part 3 - Lead: A Regulatory Success Story
Part 4 - Something My Body Needs Anyway?
Part 5 - Obesity's Elephant: Environmental Chemicals
Part 6 - Why Our Approach to Toxicology Must Change
Part 7 - Failures of U.S. Chemical Regulation
Part 8 - Cleaning Up Our Act
Part 9 - Environmental Health Research Saves Lives and Money
Part 10 - Call to Action

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