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Acute Exposure |
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Chronic Exposure |
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Acute Injury |
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Chronic Injury |
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Health Assessment |
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Organic diet in 23 elementary school children reduced urinary chlorpyrifos and malathion to non detect levels within 5 days on diet. Urine Testing, Exposure Assessment. |
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National Child Health Study: largest study ever conducted in US, 100, 000 children (0-21 y.o.). Will track for generations environmental factors in water, air, dust, soil, food, home, neighborrhood, and how it affectsbirth defects, pregnancy, illnesses, asthma, mental health, diabetes, cardiovascular effects and intellectual development. 105 study centers nationwide. List of study centers. More details of study. |
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Toxicology and medicine work closely together to assess the health effects of chemical exposure. Toxicologists rely on the clinical expertise and differential diagnoses of physicians to eliminate non chemical causes of an adverse health event, and to pinpoint the nature of the condition that could be related to a chemical exposure. Physicians must often rely on the toxicological literature for hazard and exposure assessment when presented with newly developed or exacerbated health problems that might be related to a chemical exposure.
This section discusses key concepts of toxic causation, exposure assessment and dose response of adverse health effects. It also provides sources and citations of relevant toxicological literature and offers guidelines to locate, assess and evaluate those sources and the data.
This section overlaps in many ways with The Home section, especially in discussions of maternal and childhood toxicity, and that of other high risk groups. This section addresses those issues more technically, whereas practical appllication of this information is likely to be discussed in more depth in Toxicology & The Home.
Emergency Room Physician Guide to Chemical Exposures
Hazard Assessment
Agency for Toxic Substances and Disease Registry (ATSDR) of the Centers for Disease Control (CDC) has put together a three volume series for Managing Hazardous Materials Incidents (MHMI). Volume III specifically addresses handling the patient who presents with some types of chemical exposure and covers all aspects from decontamination, to antidotes and treatment, to self protection.
Respiratory problems:
Health Assessment
Assessing the role of chemicals (and indoor air pollution) in develpment or exacerbation of asthma, RADS (single and multiple exposures), WTC Cough [see below, In Depth], non allergic hypersensitivity, chemical bronchitis. Distinctions between these disorders.
Lead exposure in children
Hazard/Exposure Assessment
CDC goals for 2010 to have all children age six and under with blood lead levels below10 ug lead/dl blood. (Mortal. Morb. Wkly Rpt, 52: 1-21 [9/12/03]) New studies show adverse neurological effects at or below this threshold, and raise new questions about protection from this new CDC goal ( Science of Toxicology ]
Fine and ultrafine particles
Hazard Assessment, Analysis
New focus on cricital role in respiratory and heart disease. Deposition of particles deep into respiratory tract and penetration into systemic circulation. Role as carrier of other adsorbed chemicals and in inflammatory response [ see In Brief and References, below ]
See also: Science of Toxicology, In Brief; Toxicology & Regulation, Spotlight ] .
Medicine
Phthalates and Baby Boys Potential Disruption of Human Genital Development: Exposure in 134 boys, measuring anogenital distance (AGI) showed dose response with maternal phthalate exposure. Implications for widespread exposure in pregnant women (EHP, 113:1056-1061).
Toxicologic Emergencies, Lewis Goldfrank, MD (2002) McGraw Hill.
Handbook of Medical Toxicology Peter Viccellio, MD. (1993) Little Brown.
Epidemiological evidence on health effects of ultrafine particles; Ibald-Mulli A, Wichmann HE, Kreyling W, Peters A; J Aerosol Med. 15(2):189-201.
Potential Role of Ultrafine Particles in Assocation between Airborne Particle Mass and Cardiovascular Health; Delfino, RJ, Sioutas, C and Malik, S. EHP (2005) 113:934-946. Ultrafine particles can migrate into systemic circulation, and very large surface area can carry fossil fuel free-radicals which cause oxidative stress and systemic inflammation.
Guidelines for Diagnosis and Management of Asthma, Expert Panel Report, NIH (1998), National Heart, Lung and Blood Institute; Update on Selected Topics (2002): http://www.nhlbi.nih.gov/guidelines/asthma/
Thyroid Hormones in Pregnancy in Relation to Environmental Exposure to Organochlorine Compounds and Mercury: Maternal concentrations of PCB, other organo pesticides and inorganic mercury were dose related to decreases in thyroid hormone, T3. These compounds pass the placental barrier.
The proportion of lung cancer cases not attributed to smoking has greatly increased in the past few decades, especially in women, in which non smoking cases has almost doubled to 20% of all cases. This is proportionately more than seen in men and may have to do with radon at home, where women continue to remain for longer periods of time. Second hand smoking effects have declined as cigarette smoking has declined, as reported in CDC study of chemicals--amount of cotine, a metabolite of nicotine, has declined in non smokers--even as the surgeon general has reported further data that strengthens the link between second hand smoke and a variety of health complaints. The data link is stronger , even as it affects fewer people.
World Trade Center Cough: Asthma-like condition that developed in emergency workers and others in the vicinity of the WTC may be a model and provide insight into acutely caused, but persistent, chemical respiratory injuries. Research and clinical evaluations to date [see WTC: Toxic Effects].
Fact Sheets of Common Poison Groups, plants, animals, marine life, insects, home products, more
Ellenhorn's Medical Toxicology, Diagnosis and Treatment of Human Poisoning. Matthew Ellenhorn, MD (1997) Williams Wilkins.
Asthma triggers poorly managed
Health Assessment
More than 70%, mainly children, could better manage asthma triggers (EPA News Release).
Manganese toxicity: doctors missing subtle effects?
Hazard Assessment
Manganese welding fume toxicity produces classic psychiatric symptoms and the 'cock walk,' a staggering, shaky gait that characterizes this toxicity. Recent research at Mayo clinic suggests a more subtle constellation of symptoms, with consistent physiological correlates, that its authors warn are often missed by attending physicians.
Mercury toxicity during preganancy: the real dangers
Exposure and Hazard Assessment
CDC and EPA analyses shows 6-7 percent of child-bearing women may have blood mercury levels above the acceptable reference dose for neurotoxic effects; as many as one percent may have levels 3.5 x the dose, potentially affecting 60, 000 to 300, 000 fetuses per year with neurodevelopmental problems.
See Also: Mercury Home page. Effect of mercury hot spots due to changes of Clean Air Act [ Toxicology & Regulation, Spotlight ]FDA-EPA Advisory for mercury-fish consumption.
Mercury - autism link
Hazard Assessment
U. Texas Health Center shows dose response relatiionship across 254 Texas counties: amount of mercury released into air versus autism rates. Implications for Clean Air Act allowance of trading mercury 'credits' which can create hotspots [ Toxicology & Regulation, Spotlight ] .
See also: Effects of manganese, another heavy metal, on neurological functioning, i.e., parkinsonism [ Science of Toxicology, News Highlights ]