Mercury use in espiritismo: a survey of botanicas

Uma revisão de escopo de revisões sistemáticas sobre exposição humana ao mercúrio

Resumo: Introdução: a promulgação da Convenção de Minamata no Brasil em 2018 incentivou o cumprimento dos seus objetivos em reduzir o uso e a poluição por mercúrio. Objetivo: caracterizar a produção científica sobre exposição humana ao mercúrio e identificar lacunas de conhecimento a fim de subsidiar a tomada de decisão em saúde. Métodos: revisão de escopo de revisões sistemáticas e metanálises, sem restrição de idioma ou data de publicação, utilizando as bases PubMed, BVS e Cochrane Library. Resultados: 71 estudos atenderam aos critérios de elegibilidade, com 40 revisões sistemáticas, 30 metanálises e 1 overview. Amálgama dentário e contaminação alimentar e ambiental por atividades que utilizam mercúrio foram as fontes de exposição mais mencionadas. Os temas mais estudados contaram com transtornos mentais e comportamentais, assim como uso de biomarcadores e testes neurocomportamentais relacionados à exposição ao mercúrio. Discussão: lacunas como a exposição ocupacional ao mercúrio, uso em práticas tradicionais e em cosméticos apontam para a necessidade de mais estudos. As revisões identificadas podem oferecer subsídios para sínteses de evidências e protocolos de atenção à saúde de populações expostas, assim como para a elaboração de políticas públicas que visem o controle do uso e da exposição ao mercúrio.

Mercury: the beginnings in the medicalization of common names of medicinal plants in Brazil

Abstract Medicalization of common names of medicinal plants is a process that involves replacing popular native names by trademarked names of drugs, active principles or therapeutic indications used by modern biomedicine. In Brazil, this process seems to have been intensified in the early 2000s due to the increasing use of those names in ethnoscientific surveys in local communities. In this study, we aimed to trace the origins of that process. For this purpose, we reviewed data from the “grey literature” pre-1980, including 15 books, compendia, dictionaries, and guides of medicinal plants. Mercury and its lexical changes were the only medicalized names found in the literature before the 1980s. This is probably due to the ancient use of mercury in several medical systems through human history, including by Brazilian apothecaries since the seventeenth century. Moreover, Mercurochrome was the name of a Brazilian trademark of antiseptic that probably influenced the use of medicalized names of mercury in the past. The name “Mercury” and its “natural” epithet combinations, like “Mercúrio-vegetal” (Mercury-plant) and “Mercúrio-do-campo” (Field-mercury), could have been the original medicalized way of naming medicinal plants in Brazil.

Modulators of mercury risk to wildlife and humans in the context of rapid global change

Environmental mercury (Hg) contamination is an urgent global health threat. The complexity of Hg in the environment can hinder accurate determination of ecological and human health risks, particularly within the context of the rapid global changes that are altering many ecological processes, socioeconomic patterns, and other factors like infectious disease incidence, which can affect Hg exposures and health outcomes. However, the success of global Hg-reduction efforts depends on accurate assessments of their effectiveness in reducing health risks. In this paper, we examine the role that key extrinsic and intrinsic drivers play on several aspects of Hg risk to humans and organisms in the environment. We do so within three key domains of ecological and human health risk. First, we examine how extrinsic global change drivers influence pathways of Hg bioaccumulation and biomagnification through food webs. Next, we describe how extrinsic socioeconomic drivers at a global scale, and intrinsic individual-level drivers, influence human Hg exposure. Finally, we address how the adverse health effects of Hg in humans and wildlife are modulated by a range of extrinsic and intrinsic drivers within the context of rapid global change. Incorporating components of these three domains into research and monitoring will facilitate a more holistic understanding of how ecological and societal drivers interact to influence Hg health risks.

Sources of Mercury Exposure to Children in Low- and Middle-Income Countries

BACKGROUND

Many children in low- and middle-income countries face enhanced risks of exposure to contaminants via the environment, parental occupation, and other routes. While mercury (Hg) is a global pollutant whose transport properties allow it to have an impact even in pristine areas, the presence of significant Hg sources in the developing world can cause localized effects that are more severe than those observed in other areas.

OBJECTIVES

This paper provides a narrative review of sources of Hg exposure to people in the developing world with a particular focus on children, and presents an overview of key aspects to this important issue.

METHODS

We searched Web of Knowledge and Google Scholar using keywords including combinations of "mercury" and one or more of the following: "children," "exposure," "breast milk," "artisanal mining," "prenatal," "religion," "medicine," "dental amalgam," "chlor-alkali," "VCM," "vaccine," "e-waste," "industry," "beauty," "cosmetics," "strategies," "child labor," "costs," and "developing countries" to find peer-reviewed articles pertaining to Hg exposure in the developing world.

RESULTS

Sources of Hg exposure include mining, consumption, industrial operations, religious practices, traditional medicines, beauty products, vaccines, dental amalgams, and waste scavenging and recycling.

CONCLUSION

Children in the developing world are often subject to higher levels of Hg exposure than those living in developed countries due to the higher prevalence of Hg-intensive industrial processes and consumer products, lack of environmental regulation, and limits in mobility and food choices, among other factors. This issue can be addressed through additional research to fill in data gaps on exposure sources, establish sound and enforceable policies, and increase education and participation in affected communities. Challenges to addressing this problem include limited resources for needed equipment, training, and manpower to implement solutions.

Elemental mercury poisoning presenting as hypertension in a young child

Mercury intoxication is an uncommon cause of hypertension in children and can mimic several other diseases, such as pheochromocytoma and vasculitis. Mercury intoxication can present as a diagnostic challenge because levels of catecholamines may be elevated, suggesting that the etiology is a catecholamine-secreting tumor. Once acrodynia is identified as a primary symptom, a 24-hour urine mercury level can confirm the diagnosis. Inclusion of mercury intoxication in the differential diagnosis early on can help avoid unnecessary and invasive diagnostic tests and therapeutic interventions. We discuss a case of mercury intoxication in a 3-year-old girl presenting with hypertension and acrodynia, without a known history of exposure. Chelation therapy successfully treated our patient's mercury intoxication. However, it was also necessary to concurrently treat her hypertension and the pain associated with her acrodynia. Because there were no known risk factors for mercury poisoning in this case, and because ritual use of mercury is common in much of the United States, we recommend high clinical suspicion and subsequent testing in all cases of acrodynia.

Acrodynia and hypertension in a young girl secondary to elemental mercury toxicity acquired in the home

Acrodynia, also known as pink disease, erythredema polyneuropathy, Feer syndrome, and raw-beef hands and feet, is thought to be a toxic reaction to elemental mercury and less commonly to organic and inorganic forms. Occurring commonly in the early 20th century, acrodynia is now a seemingly extinct disease in the modern world because of regulations to eliminate mercury from personal care products, household items, medications, and vaccinations. We present a case of a 3-year-old girl with acrodynia secondary to toxic exposure to elemental mercury in the home environment.

Assessment of prenatal mercury exposure in a predominately Caribbean immigrant community in Brooklyn, NY

Prenatal mercury exposure and its fetotoxic effects may be of particular concern in urban immigrant communities as a result of possible contributing cultural factors. The most common source of exposure in these communities is ingestion of fish and shellfish contaminated with methylmercury. Other sources of exposure may occur in ritualistic practices associated with Hispanic and Caribbean-based religions. This study 1) assessed total mercury levels in both random urine specimens from pregnant women, and in cord blood; and 2) examined environmental sources of exposure from a convenience sample in a predominantly Caribbean immigrant population in Brooklyn, New York. A questionnaire designed in collaboration with health professionals from the Caribbean community assessed the frequency of fish consumption, ritualistic practices, occupational exposures, and use of dental amalgams and mercury-containing skin and household products. The geometric mean for total mercury in cord blood was 2.14 μg L(-1) (95%CI: 1.76-2.60) (n = 78), and 0.45 μg L(-1) (95%CI: 0.37-0.55) (n = 183) in maternal urine corrected for creatinine (μg g(-1)). Sixteen percent of cord blood mercury levels exceeded the estimated equivalent of U.S. Environmental Protection Agency's Reference Dose (5.8 μg L(-1) blood). Predictors of cord blood mercury included maternal fish consumption and foreign birth of the mother. Predictors of urine mercury included foreign birth of the mother, number of dental amalgams, and special product use. There were no reports of mercury use in ritualistic practices or in cosmetics; however some women reported use of religious medals and charms. This study characterized risk factors for mercury exposure in a sample of urban, predominantly Caribbean-born blacks. Findings may help target interventions in this population, which might include appropriate fish selection and consumption frequency during pregnancy, and safe handling of mercury-containing products in the home.

A review of events that expose children to elemental mercury in the United States

Concern for children exposed to elemental mercury prompted the Agency for Toxic Substances and Disease Registry and the Centers for Disease Control and Prevention to review the sources of elemental mercury exposures in children, describe the location and proportion of children affected, and make recommendations on how to prevent these exposures. In this review, we excluded mercury exposures from coal-burning facilities, dental amalgams, fish consumption, medical waste incinerators, or thimerosal-containing vaccines. We reviewed federal, state, and regional programs with data on mercury releases along with published reports of children exposed to elemental mercury in the United States. We selected all mercury-related events that were documented to expose (or potentially expose) children. Primary exposure locations were at home, at school, and at others such as industrial property not adequately remediated or medical facilities. Exposure to small spills from broken thermometers was the most common scenario; however, reports of such exposures are declining. The information reviewed suggests that most releases do not lead to demonstrable harm if the exposure period is short and the mercury is properly cleaned up. Primary prevention should include health education and policy initiatives.

A review of events that expose children to elemental mercury in the United States

OBJECTIVE

Concern for children exposed to elemental mercury prompted the Agency for Toxic Substances and Disease Registry and the Centers for Disease Control and Prevention to review the sources of elemental mercury exposures in children, describe the location and proportion of children affected, and make recommendations on how to prevent these exposures. In this review, we excluded mercury exposures from coal-burning facilities, dental amalgams, fish consumption, medical waste incinerators, or thimerosal-containing vaccines.

DATA SOURCES

We reviewed federal, state, and regional programs with information on mercury releases along with published reports of children exposed to elemental mercury in the United States. We selected all mercury-related events that were documented to expose (or potentially expose) children. We then explored event characteristics (i.e., the exposure source, location).

DATA SYNTHESIS

Primary exposure locations were at home, at school, and at other locations such as industrial property not adequately remediated or medical facilities. Exposure to small spills from broken thermometers was the most common scenario; however, reports of such exposures are declining.

DISCUSSION AND CONCLUSIONS

Childhood exposures to elemental mercury often result from inappropriate handling or cleanup of spilled mercury. The information reviewed suggests that most releases do not lead to demonstrable harm if the exposure period is short and the mercury is properly cleaned up.

RECOMMENDATIONS

Primary prevention should include health education and policy initiatives. For larger spills, better coordination among existing surveillance systems would assist in understanding the risk factors and in developing effective prevention efforts.

Mercury exposure in young children living in New York City

Residential exposure to vapor from current or previous cultural use of mercury could harm children living in rental (apartment) homes. That concern prompted the following agencies to conduct a study to assess pediatric mercury exposure in New York City communities by measuring urine mercury levels: New York City Department of Health and Mental Hygiene's (NYCDOHMH) Bureau of Environmental Surveillance and Policy, New York State Department of Health/Center for Environmental Health (NYSDOHCEH), Wadsworth Center's Biomonitoring Program/Trace Elements Laboratory (WC-TEL), and Centers for Disease Control and Prevention (CDC). A previous study indicated that people could obtain mercury for ritualistic use from botanicas located in Brooklyn, Manhattan, and the Bronx. Working closely with local community partners, we concentrated our recruiting efforts through health clinics located in potentially affected neighborhoods. We developed posters to advertise the study, conducted active outreach through local partners, and, as compensation for participation in the study, we offered a food gift certificate redeemable at a local grocer. We collected 460 urine specimens and analyzed them for total mercury. Overall, geometric mean urine total mercury was 0.31 microg mercury/l urine. One sample was 24 microg mercury/l urine, which exceeded the (20 microg mercury/l urine) NYSDOH Heavy Metal Registry reporting threshold for urine mercury exposure. Geometric mean urine mercury levels were uniformly low and did not differ by neighborhood or with any clinical significance by children's ethnicity. Few parents reported the presence of mercury at home, in a charm, or other item (e.g., skin-lightening creams and soaps), and we found no association between these potential sources of exposure and a child's urinary mercury levels. All pediatric mercury levels measured in this study were well below a level considered to be of medical concern. This study found neither self-reported nor measured evidence of significant mercury use or exposure among participating children. Because some participants were aware of the possibility that they could acquire and use mercury for cultural or ritualistic purposes, community education about the health hazards of mercury should continue.

Incorporating ethnographic methods in multidisciplinary approaches to risk assessment and communication: cultural and religious uses of mercury in Latino and Caribbean communities

The potential risk from cultural and religious practices involving mercury in Latino and Caribbean communities raises central methodological and ethical questions for risk assessment and risk communication. Here, specific cultural practices unfamiliar to most risk professionals carry significant inherent risks in the eyes of those professionals but not necessarily in the eyes of practitioners. Practitioners' past experience and history as targets of religious suppression and anti-immigrant sentiment create a reluctance to engage with researchers or public health officials in risk assessment or preventive risk communication efforts. The potential for the risk--in this case mercury contamination in dwellings--to extend beyond the practicing community to future occupants adds to public health concern. Understanding the risks of these practices requires both an understanding of the cultural and political context, beliefs, and behaviors of mercury users and an understanding of the fate and transport of mercury in typical use scenarios. In this study, we employed ethnographic methods (interviews and participant observation) to understand beliefs and behavior about mercury use as well as quantitative modeling and measurement to estimate and assess potential exposures. This represents a new methodology tailored to situations in which traditional activities or observances that are integral components of cultural identity pose risks in and of themselves. Our findings indicate that there are different types of mercury use stemming from different cultural and religious traditions that result in different levels of exposure. Many of the mercury uses that can result in the highest exposures to mercury vapors have previously been attributed to the religious tradition of Santeria, but appear instead to have their roots outside of the religion.

Mercury use and exposure among Santeria practitioners: religious versus folk practice in Northern New Jersey, USA

OBJECTIVE

To understand and characterize exposure to and use of elemental mercury among practitioners of Afro-Cuban religions in Hudson County, New Jersey, USA.

DESIGN

Participant observation and open-ended interviews with 22 religious supply store employees and practitioners of Santeria, Espiritismo or Palo Mayombe probed respondents' knowledge and use of mercury, as well as their beliefs about its benefits and risks. Including a cultural and religious insider as part of the research team was crucial in working with this relatively closed community.

RESULTS

Seventeen of the 21 practitioners reported using mercury or mercury compounds in various forms of practice and in services that they provide to clients. The contained nature of these uses suggests that accidental spills, as opposed to the practices themselves, emerge as the greatest exposure concern for this population. Mercury was never recommended to clients for individual use. This restriction appears to be rooted in the way the religion is practiced and in the way santeros receive compensation, not in a perception of mercury as hazardous. Most practitioners were aware that mercury can be hazardous, but were not familiar with the most significant exposure pathway, inhalation of mercury vapor. A climate of fear surrounds the use of mercury in this community, so that health concerns pale in comparison to fear of reprisal from authorities. Among those who sell or formerly sold mercury, several shared the erroneous belief that it was illegal to sell mercury in New Jersey.

CONCLUSION

Despite widespread reported use, there were no reports of practices believed to result in the highest exposures. To reduce exposure in the community, interventions presenting general information on mercury hazards and instructions for cleaning up spills are recommended. To address insider-outsider dynamics and the climate of fear, educational materials should be accessible to the community and avoid any mention of religious practice.

Comparison of indoor mercury vapor in common areas of residential buildings with outdoor levels in a community where mercury is used for cultural purposes

Elemental mercury has been imbued with magical properties for millennia, and various cultures use elemental mercury in a variety of superstitious and cultural practices, raising health concerns for users and residents in buildings where it is used. As a first step in assessing this phenomenon, we compared mercury vapor concentration in common areas of residential buildings versus outdoor air, in two New Jersey cities where mercury is available and is used in cultural practices. We measured mercury using a portable atomic absorption spectrometer capable of quantitative measurement from 2 ng/m3 mercury vapor. We evaluated the interior hallways in 34 multifamily buildings and the vestibule in an additional 33 buildings. Outdoor mercury vapor averaged 5 ng/m3; indoor mercury was significantly higher (mean 25 ng/m3; p<0.001); 21% of buildings had mean mercury vapor concentration in hallways that exceeded the 95th percentile of outdoor mercury vapor concentration (17 ng/m3), whereas 35% of buildings had a maximum mercury vapor concentration that exceeded the 95th percentile of outdoor mercury concentration. The highest indoor average mercury vapor concentration was 299 ng/m3, and the maximum point concentration was 2,022 ng/m3. In some instances, we were able to locate the source, but we could not specifically attribute the elevated levels of mercury vapor to cultural use or other specific mercury releases. However, these findings provide sufficient evidence of indoor mercury source(s) to warrant further investigation.

Mercury exposure: medical and public health issues

Mercury exposure is widespread in the United States with methylmercury as the predominant chemical species and fish and shellfish as the source. Use of more advanced diagnostic techniques and application of population-based risk assessment methodologies have assisted in addressing the impact of mercury exposure on the United States population. Biomonitoring, particularly through analyses of blood mercury, provides both population-based data and exposure information that can be informative for physicians. Data from the National Health and Nutrition Examination Survey (NHANES) beginning in 1999 provide population-based exposure estimates for United States overall. Methylmercury exposures among women of childbearing age are of particular concern because of methylmercury's developmental neurotoxicity. Exposures of concern among women are estimated to occur in between approximately 6% to 8% of the 16-to-49-year-old age group based on data from NHANES; and in approximately 15% of this age and sex group if physiological factors such as the degree of transplacental transport of methylmercury are taken into consideration. Subgroups with high fish consumption (e.g., many island and coastal populations, some persons of Asian ethnicity, some individuals following "healthy" diets) can have methylmercury exposures substantially higher than those reported among the NHANES examinees. These subpopulations are not likely to be aware of their blood mercury concentrations or the possible health outcomes associated with such high blood mercury levels. The American Medical Association has adopted policies that express concerns about methylmercury exposure, and advise patient education. Non-neurological risks for adults associated with methylmercury, including the potential for adverse cardiac outcomes, have not yet been incorporated into risk assessments.

Subcutaneous injection of mercury: "warding off evil"

Deliberate injection of mercury, especially subcutaneous injection, is rare but is seen in psychiatric patients, individuals who attempt suicide, those who are accidentally injected, and boxers who wish to build muscle bulk. Metallic mercury plays a major role in ethnic folk medicine. Neurologic and renal complications can result from high systemic levels of mercury, and subcutaneous injection usually results in sterile abscesses. Urgent surgical evacuation and close monitoring for neurologic and renal functions as well as chelation (if toxicity is indicated) are key aspects of treatment. Education of the adverse effects and dangers of mercury is important, especially in pregnant women and children. As increased immigration changes demographic patterns, proper disposal of mercury and preventing its sale and use should become urgent societal priorities. Psychiatric consultation should be obtained whenever appropriate.

Mercury exposure in children: a review

Exposure to toxic mercury (Hg) is a growing health hazard throughout the world today. Recent studies show that mercury exposure may occur in the environment, and increasingly in occupational and domestic settings. Children are particularly vulnerable to Hg intoxication, which may lead to impairment of the developing central nervous system, as well as pulmonary and nephrotic damage. Several sources of toxic Hg exposure in children have been reported in biomedical literature: (1) methylmercury, the most widespread source of Hg exposure, is most commonly the result of consumption of contaminated foods, primarily fish; (2) ethylmercury, which has been the subject of recent scientific inquiry in relation to the controversial pediatric vaccine preservative thimerosal; (3) elemental Hg vapor exposure through accidents and occupational and ritualistic practices; (4) inorganic Hg through the use of topical Hg-based skin creams and in infant teething powders; (5) metallic Hg in dental amalgams, which release Hg vapors, and Hg2+ in tissues. This review examines recent epidemiological studies of methylmercury exposure in children. Reports of elemental Hg vapor exposure in children through accidents and occupational practices, and the more recent observations of the increasing use of elemental Hg for magico-religious purposes in urban communities are also discussed. Studies of inorganic Hg exposure from the widespread use of topical beauty creams and teething powders, and fetal/neonatal Hg exposure from maternal dental amalgam fillings are reviewed. Considerable attention was given in this review to pediatric methylmercury exposure and neurodevelopment because it is the most thoroughly investigated Hg species. Each source of Hg exposure is reviewed in relation to specific pediatric health effects, particularly subtle neurodevelopmental disorders.

Mercury exposure in an urban pediatric population

OBJECTIVE

To determine the prevalence of elevated urinary mercury (Hg), as a marker of exposure, in a population of children drawn from an inner-city community with documented access to elemental mercury.

METHODS

A prospective consecutive patient series was conducted from November 1998 to January 1999 at an inner-city clinic in New York. Anonymous urine specimens from subjects (aged 1-18 years) were collected in mercury-free containers, split, acidified with 1:100 hydrochloric acid, and frozen. Cold-vapor atomic absorption spectrofluorometric assays were conducted simultaneously at laboratories at the University of Washington and the New York City Department of Health.

RESULTS

We enrolled 100 children (mean age 9.4 years; 62% male; 55% Hispanic; and 43% African American). Assay results from both laboratories were strongly correlated (r = 0.8, P <.0001). Mean urinary Hg was 1.08 +/- 1.82 microg/L. The 95th percentile for urinary Hg was 2.8 microg/L (range 0.2 to 11.7 microg/L). Five subjects had Hg levels above 5 microg/L.

CONCLUSION

We found that 5% of subjects had unsuspected elevated urinary Hg levels. This finding, in a group of inner-city minority children, strongly supports the need for further investigation of the sources of mercury exposure in this population.

Combining community-based research and local knowledge to confront asthma and subsistence-fishing hazards in Greenpoint/Williamsburg, Brooklyn, New York

Activists in the environmental justice movement are challenging expert-driven scientific research by taking the research process into their own hands and speaking for themselves by defining, analyzing, and prescribing solutions for the environmental health hazards confronting communities of the poor and people of color. I highlight the work of El Puente and The Watchperson Project--two community-based organizations in the Greenpoint/Williamsburg neighborhood in Brooklyn, New York, that have engaged in community-based participatory research (CBPR) to address asthma and risks from subsistence-fish diets. The CBPR process aims to engage community members as equal partners alongside scientists in problem definition, information collection, and data analysis--all geared toward locally relevant action for social change. In the first case I highlight how El Puente has organized residents to conduct a series of asthma health surveys and tapped into local knowledge of the Latino population to understand potential asthma triggers and to devise culturally relevant health interventions. In a second case I follow The Watchperson Project and their work surveying subsistence anglers and note how the community-gathered information contributed key data inputs for the U.S. Environmental Protection Agency Cumulative Exposure Project in the neighborhood. In each case I review the processes each organization used to conduct CBPR, some of their findings, and the local knowledge they gathered, all of which were crucial for understanding and addressing local environmental health issues. I conclude with some observations about the benefits and limits of CBPR for helping scientists and communities pursue environmental justice.

Folk use of elemental mercury: a potential hazard for children?

Human beings have used elemental mercury (also known as metallic mercury) for thousands of years. Early ignorance of its potential toxicity resulted in devastating adverse effects, including neurodevelopmental and behavioral deficits among exposed persons. These adverse effects most commonly resulted from exposure to the vapor of elemental mercury. Recognition of the toxicity of elemental mercury has led to strict regulation of its use in occupational settings.

Assessing elemental mercury vapor exposure from cultural and religious practices

Use of elemental mercury in certain cultural and religious practices can cause high exposures to mercury vapor. Uses include sprinkling mercury on the floor of a home or car, burning it in a candle, and mixing it with perfume. Some uses can produce indoor air mercury concentrations one or two orders of magnitude above occupational exposure limits. Exposures resulting from other uses, such as infrequent use of a small bead of mercury, could be well below currently recognized risk levels. Metallic mercury is available at almost all of the 15 botanicas visited in New York, New Jersey, and Pennsylvania, but botanica personnel often deny having mercury for sale when approached by outsiders to these religious and cultural traditions. Actions by public health authorities have driven the mercury trade underground in some locations. Interviews indicate that mercury users are aware that mercury is hazardous, but are not aware of the inhalation exposure risk. We argue against a crackdown by health authorities because it could drive the practices further underground, because high-risk practices may be rare, and because uninformed government intervention could have unfortunate political and civic side effects for some Caribbean and Latin American immigrant groups. We recommend an outreach and education program involving religious and community leaders, botanica personnel, and other mercury users.

Treatment of mercury intoxication

The element mercury exists as inorganic, elemental, or organic species. Routes of exposure and toxicity in humans vary according to the species of mercury involved. Treatment of mercury poisoning generally requires the use of sulfhydryl bond-containing chelation agents, including the parenterally administered dimercaprol and its oral congeners. These oral chelators, meso-2,3-dimercaptosuccinic acid and sodium 2,3-dimercapto-1-propanesulfonate, have numerous advantages over dimercaprol, including less toxicity. Although dimercaprol is contraindicated in organic mercury exposures, meso-2,3-dimercaptosuccinic acid and sodium 2,3-dimercapto-1-propanesulfonate may be used to chelate all species of mercury. Recent evidence suggests that their efficacy in organic mercury poisoning is uncertain.

Missed diagnoses and misdiagnoses of environmental toxicant exposure. The psychiatry of toxic exposure and multiple chemical sensitivity

Toxins such as carbon monoxide, lead, and mercury that present occasionally with primarily psychiatric symptoms can pose some of the most difficult diagnoses. This article reviews the clues that can allow the diagnostician to identify the role of one of these substances. Equally important, the article discusses the contentious issues that surround the phenomen known as multiple chemical sensitivity. Viewed primarily as a functional illness, often with legal overtones, this putative disorder is critically reviewed to see if it meets the same demanding standard of validity that is found in the psychiatric symptoms associated with other toxic disorders. Although questioning the strict medical origin of medical chemical sensitivity, the article outlines some treatment hints that may helpful in the management of this difficult group of patients.

The dangers of using herbs. What your patients need to know

Herbal remedies are becoming increasingly popular among patients as treatment for such varied medical problems as arthritis, depression, diabetes, menstrual irregularity, and pulmonary conditions. However, there are many negative effects of herbal preparations. Dr Borins discusses the potential side effects of various herbs and the lack of standardization and control that can contribute to contamination and toxicity of herbal products.