Erik Rifkin

Combination of diffusive gradient in a thin film probe and IC-ICP-MS for the simultaneous determination of CH3Hg+ and Hg2+ in oxic water.

A diffusive gradient in thin film technique (DGT) was combined with ion chromatography and inductively coupled plasma mass spectrometry (IC-ICP-MS) for the in situ simultaneous quantification of CH(3)Hg(+) and Hg(2+) in aquatic environments. After diffusing through an agarose diffusive layer, the Hg species accumulated in a thiol-functionalized resin layer and were extracted using acidic thiourea solution to form stable thiourea-Hg complexes that were separated and detected via ion chromatography and ICP-MS, respectively. The effective diffusion coefficients of CH(3)Hg(+) and Hg(2+) complexes in the agarose diffusion layer with chloride were 5.26 (±0.27) × 10(-6) and 4.02 (±0.10) × 10(-6) cm(2) s(-1), respectively. The effective diffusion coefficients of CH(3)Hg(+) and Hg(2+) complexes in the agarose diffusion layer with dissolved organic matter was 3.57 (±0.29) × 10(-6) and 2.16 (±0.19) × 10(-6) cm(2) s(-1), respectively. The practical method detection limits are 0.1 and 0.7 ng L(-1) for CH(3)Hg(+) and Hg(2+) respectively for three weeks deployment. Lower detection limits would be possible by employing a thinner agarose diffusive layer and/or by deploying the probes longer. The method can measure time averaged CH(3)Hg(+) and Hg(2+) concentrations simultaneously in oxic water, making it useful as an in situ monitoring tool.

Dioxin bioaccumulation: Key to a sound risk assessment methodology

Human exposure to many pollutants occurs primarily through the ingestion of contaminated fish. In order to protect human health, regulatory agencies set limits on the levels of pollutants entering water bodies from point sources, thereby limiting the amount of pollutants that may be accumulated by fish. The limits, in the form of water quality criteria, are designed to correlate the concentration of a pollutant in a water body (and therefore the concentration accumulated by a fish) to the risks to humans. This type of model provides a reasonable way of controlling pollutants from point sources if the assumptions used in the model are realistic. However, the risk assessment formula currently used for developing water quality criteria only considers those pollutants in the water column available to fish through bioconcentration across the gills (freely dissolved pollutants). For strongly hydrophobic pollutants like dioxin, an extremely small fraction of the total amount is freely dissolved; most dioxin is sorbed to organic matter and is ingested by fish. A new model for developing criteria is presented here that takes into account the environmental fate of dioxin (predominantly in the sorbed state in the environment) and that fish accumulate dioxin by ingestion, rather than bioconcentration.

Health Effects of Smoking

The 2004 US Surgeon General’s Report on the Health Consequences of Smoking reviewed and cited over 1,600 different sources. Taken all together, some of this evidence is so convincing that the Report infers a cause and effect relationship between smoking and certain diseases: lung cancer, oral cancer, bladder cancer, cervical cancer, coronary heart disease, stroke, chronic obstructive pulmonary disease (emphysema and chronic bronchitis), reduced female fertility, premature delivery, and even cataracts. While benefits of not smoking are clear and well defined, smoking continues to be prevalent throughout the world. A unique graphic, functioning as a decision aid, has been developed to enable physicians and patients to jointly assess the risks associated with smoking cigarettes. Findings of two major studies are presented in a way that puts the complexities of risk analysis in terms patients can understand. Therefore, patients will be empowered to make well-informed decisions about their health. This decision aid has been successfully used to assist patients in determining their level of acceptable risk.

Involving the Patient in Decision Making

Through the eyes of a practicing primary care physician, the benefits and difficulties of office based shared decision making are discussed in this chapter. Both doctors and patients often obtain their medical information from unreliable sources, whether the internet, media, or medical studies that present information in the language of relative risk/benefit. Such confusing data impedes the ability to carry out a mutually beneficial conversation about medical issues during an office visit. Also, due to the lack of good decision aids, logistical problems and time constraints also preclude shared decision making. The authors discuss important considerations that are needed to assess medical tests and procedures such as accurately knowing false positive and negative results, looking at clinical rather than numerical outcomes, and evaluating patient goals of treatment including the ability to determine meaningful risks and benefits. We demonstrate how a unique graphic decision aid can help to attain these goals in a way that is pragmatic for doctor and patient in the setting of a busy office visit.

Towards a Universal Decision Aid

The assortment of decision aids (e.g., video, audio tapes, flyers) currently being used has resulted in the absence of a uniform set of criteria or standards which are needed to ensure the effectiveness and increased use of future decision aids. In order for this communication tool to be successful, it should include a visual display that enables the reader to look at an image and be able to readily determine risks and benefits from screening tests (e.g., colonoscopy, PSA test, mammogram, cholesterol), drugs (e.g., statins, CoumadinTM), and surgeries for a number of health endpoints. Most people are familiar with the crowd in a typical theater as a graphic illustration of a population grouping. Therefore, a theater seating chart could be used to objectively characterize and communicate health benefits and risks. This led to the development of a decision aid called a Benefit/Risk Characterization Theater (BRCT). It has been successfully used to assist patients in determining their level of acceptable risk. With a seating capacity of 1,000, this BRCT makes shared decision making straight forward and a positive experience for doctor and patient. Presenting information in this format requires the use of absolute values and eliminates the use of relative risks which often leads to the dissemination of misinformation.

Statins, Cholesterol, and Coronary Heart Disease

Statins—VytorinTM, LipitorTM, LovastatinTM, CrestorTM, PravastatinTM , and SimvastatinTM—are the most widely used prescription drugs in the world. New treatment guidelines for high cholesterol will likely increase the number of individuals prescribed these drugs. Clinical trials demonstrate that statins reduce the incidence of coronary heart disease for people with a history of coronary heart disease (CHD) and to a lesser extent, for individuals without a history of CHD. Statins can cause side effects and complications like rhabdomyolysis (muscle destruction); abnormal changes in liver function; myopathy (muscle disease); cataracts; and sexual dysfunction. Some of these side effects can affect a significant number of people. There continues to be confusion regarding the benefits of statins and subsequent risks associated with taking these drugs. Information presented to doctors and patients tends to be misleading and difficult to interpret. This is due, in large part, to the use of relative risks rather than absolute values when communicating information on the benefits of taking statins. In light of this situation, a unique graphic functioning as a decision aid has been developed to enable physicians and patients to jointly assess the benefits and risks of statin use. By characterizing the complexities of risk analysis in terms doctors can understand, patients will be able to make well-informed decisions about their health.

Antibiotics in Sinusitis and Bronchitis

Sinusitis and bronchitis lead to a large number of doctor visits every year. Approximately 30 million Americans are diagnosed with sinusitis annually, with 800 out of 1,000 people receiving antibiotics, although 980–990 out of 1,000 cases are likely not caused by bacterial infection. The vast majority (900/1,000) of sinus and bronchial infections resolve after ten days without treatment. It is felt antibiotics may help 50 out of 1,000 people who use them, while 100 out of 1,000 antibiotic users experience side effects when compared to placebo. There continues to be confusion regarding the benefits and risks of antibiotic use in sinusitis and bronchitis. Information presented to doctors and patients tends to be misleading and difficult to interpret. This is due, in large part, to the use of relative risks rather than absolute values when communicating information on antibiotic benefits. In light of this situation, a unique graphic, functioning as a decision aid, has been developed to enable physicians and patients to jointly assess the benefits and risks of antibiotic use. By characterizing the complexities of risk analysis in terms patients can understand, means they will be able to make well-informed decisions about their health.

Osteoporosis: Bone Density Testing and Drug Treatment

Osteoporosis puts people at risk for serious fractures, such as broken hips. The incidence of osteoporosis increases with age, with 400 out of 1,000 people over 80 having osteoporosis. Since hip fractures cause significant disability and mortality, many people seek to diagnose and treat osteoporosis with drugs such as bisphosphonates. Studies show that 1–2 people avert a hip fracture over 3 years among 1,000 who take bisphosphonates. After 5 years there is an increased risk of fracture with use of these drugs. Nevertheless, there continues to be confusion regarding the benefits of osteoporosis screening and subsequent risks associated with medical intervention. Information presented to doctors and patients tends to be misleading and difficult to interpret. This is due, in large part, to the use of relative risks rather than absolute values when communicating information on osteoporosis screening benefits. In light of this situation, a unique graphic, functioning as a decision aid, has been developed to enable physicians and patients to jointly assess the benefits and risks of osteoporosis screening and eventual medical intervention. By characterizing the complexities of risk analysis in terms patients can understand, means they will be able to make well-informed decisions about their health.

Estrogen Replacement Therapy

Menopausal symptoms are common and can be uncomfortable and even debilitating. Estrogen can markedly reduce such symptoms in 900 out of 1,000 women who take it. In a large study, it was found that women who took estrogen have increased risk of breast cancer, leg clots, and nonfatal strokes, although many women in the study were older. Recent studies conducted on women who start estrogen close to the time of menopause actually show that 6–23 out of 1,000 people who take estrogen when compared to placebo live longer, with reduction in cancer and cardiac events. Nevertheless, there continues to be confusion regarding the benefits and risks of estrogen replacement. Information presented to doctors and patients tends to be misleading and difficult to interpret. This is due, in large part, to the use of relative risks rather than absolute values when communicating information on estrogen replacement. In light of this situation, a unique graphic, functioning as a decision aid, has been developed to enable physicians and patients to jointly assess the benefits and risks of estrogen replacement. By characterizing the complexities of risk analysis in terms patients can understand, means they will be able to make well-informed decisions about their health.

Screening for Lung Cancer with Spiral CT

Lung cancer is a deadly consequence of smoking. The lifetime risk of smokers getting lung cancer is 172/1,000, and while smoking causes 480,000 deaths a year, half of them are from lung cancer. CT scans can potentially detect lung cancer early when they may be amenable to cure. Recent studies show that smokers and ex-smokers who undergo annual CT screens can prevent 3.3 lung cancer deaths over five years out of 1,000 people screened. Such screening also leads to 675/1,000 false positives and a large number of unnecessary tests and procedures. Nevertheless, there continues to be confusion regarding the benefits of lung cancer screening and subsequent risks associated with medical intervention. Information presented to doctors and patients tends to be misleading and difficult to interpret. This is due, in large part, to the use of relative risks rather than absolute values when communicating information on lung cancer screening benefits. In light of this situation, a unique graphic, functioning as a decision aid, has been developed to enable physicians and patients to jointly assess the benefits and risks of lung cancer screening and eventual medical intervention. By characterizing the complexities of risk analysis in terms patients can understand, means they will be able to make well-informed decisions about their health.