Public health consequences among first responders to emergency events associated with illicit methamphetamine laboratories--selected states, 1996-1999.
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Methamphetamine, a central nervous system stimulant, is manufactured in illicit laboratories using over-the-counter ingredients. Many of these ingredients are hazardous substances that when released from active or abandoned methamphetamine laboratories can place first responders at risk for serious injuries and death. In 16 states, the Agency for Toxic Substances and Disease Registry maintains the Hazardous Substances Emergency Events Surveillance (HSEES) system to collect and analyze data about the morbidity and mortality associated with hazardous substance-release events. Based on events reported to HSEES during 1996-1999, this report describes examples of events associated with illicit methamphetamine laboratories that resulted in injuries to first responders in three states, summarizes methamphetamine-laboratory events involving injured first responders, and suggests injury prevention methods to protect first responders. (+info)
Alleged misconceptions' distort perceptions of environmental cancer risks.
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In a series of papers, Ames and colleagues allege that the scientific and public health communities have perpetuated a series of 'misconceptions' that resulted in inaccurate identification of chemicals that pose potential human cancer risks, and misguided cancer prevention strategies and regulatory policies. They conclude that exposures to industrial and synthetic chemicals represent negligible cancer risks and that animal studies have little or no scientific value for assessing human risks. Their conclusions are based on flawed and untested assumptions. For instance, they claim that synthetic residues on food can be ignored because 99.99% of pesticides humans eat are natural, chemicals in plants are pesticides, and their potential to cause cancer equals that of synthetic pesticides. Similarly, Ames does not offer any convincing scientific evidence to justify discrediting bioassays for identifying human carcinogens. Ironically, their arguments center on a ranking procedure that relies on the same experimental data and extrapolation methods they criticize as being unreliable for evaluating cancer risks. We address their inconsistencies and flaws, and present scientific facts and our perspectives surrounding Ames' nine alleged misconceptions. Our conclusions agree with the International Agency for Research on Cancer, the National Toxicology Program, and other respected scientific organizations: in the absence of human data, animal studies are the most definitive for assessing human cancer risks. Animal data should not be ignored, and precautions should be taken to lessen human exposures. Dismissing animal carcinogenicity findings would lead to human cancer cases as the only means of demonstrating carcinogenicity of environmental agents. This is unacceptable public health policy. (+info)
Occupational biohazards in agricultural dusts from India.
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Sixteen samples of settled dusts deposited during handling of various granular plant materials (green gram, red gram, amaranth, rice, pearl millet, sorghum, wheat, maize) in small food storing and processing facilities (godowns) were collected in the region of Aurangabad (Southern India). The samples were examined by the dilution plating method for the concentration and species composition of Gram-positive mesophilic bacteria, Gram-negative mesophilic bacteria, thermophilic actinomycetes and fungi. They were also examined by Limulus test for the concentration of bacterial endotoxin. The total concentration of microorganisms (bacteria + fungi) in examined samples varied within a wide range of 1.4 x 10(5) - 8.45 x 10(8) cfu/g (median 8.36 x 10(6) cfu/g). On average, the most common were Gram-positive bacteria (87.84% of all isolates) followed by Gram-negative bacteria (11.12%). Less common were fungi (1.24%) and thermophilic actinomycetes (0.01%). Among isolated bacteria and fungi, there were many species known as causative agents of allergic alveolitis, asthma and organic dust toxic syndrome. The concentration of bacterial endotoxin in the examined samples ranged between 12.5 - 62500 microg/g (median 781.25 microg/g), being particularly large in the samples of dust from maize (6250 microg/g and 62500 microg/g) and pearl millet (6250 microg/g and 12500 microg/g). The results of the present work indicate that the agricultural dusts from India represent a potential hazard for the workers because of high concentrations of allergenic microorganisms and bacterial endotoxin. The particular risk is associated with handing of maize and pearl millet. Further studies on this subject with the use of aerobiological methods are highly desirable (+info)
Prospective study of hepatic, renal, and haematological surveillance in hazardous materials firefighters.
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OBJECTIVES: To evaluate possible health effects related to work with hazardous materials as measured by end organ effect markers in a large cohort over about 2 years, and in a subcohort over 5 years. METHODS: Hepatic, renal, and haematological variables were analysed from 1996-98 in hazardous materials firefighters including 288 hazardous materials technicians (81%) and 68 support workers (19%). The same end organ effect markers in a subcohort of the technicians were also analysed (n=35) from 1993-98. Support workers were considered as controls because they are also firefighters, but had a low potential exposure to hazardous materials. RESULTS: During the study period, no serious injuries or exposures were reported. For the end organ effect markers studied, no significant differences were found between technicians and support workers at either year 1 or year 3. After adjustment for a change in laboratory, no significant longitudinal changes were found within groups for any of the markers except for creatinine which decreased for both technicians (p<0.001) and controls (p<0.01). CONCLUSIONS: Health effects related to work are infrequent among hazardous materials technicians. Haematological, hepatic, and renal testing is not required on an annual basis and has limited use in detecting health effects in hazardous materials technicians. (+info)
Self-reported skin problems among physical processors in the chemical industry in Great Britain.
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Contact dermatitis is common in the chemical industry. A cross-sectional study was conducted to investigate the prevalence of self-reported skin problems in employees involved in the drying, blending, milling, grinding and filling/bagging end of chemical manufacture in small- to medium-sized contract manufacturing/processing chemical companies in Great Britain. There were several secondary aims. Twenty-three per cent of the employees interviewed reported having had a skin problem in the previous 12 months. Of those reporting problems, 46% were always/nearly always involved in blending and 56% were always/nearly always involved in filling and bagging. These same processes were also more commonly associated with continuous or recurring skin problems. Seventy-five per cent reported a problem involving the upper limbs; most had more than one body area affected. Forty-three per cent had consulted a doctor (67% their general practitioner) and 9% took time off work as a result of their skin condition. Skin problems seemed to peak (34% employees) in those who had spent between 1 and 2 years in their current job. Solvents, known skin irritants, were the most frequent, single category of chemicals encountered in the study. Over 92% had been told how to avoid skin problems; 85% reported that they always/almost always wore protective clothing. Despite these measures, a significant number had reported having had a skin problem related to their work in the previous 12 months. Particular attention to control measures based on risk assessment is recommended for these physical processors in the chemical industry. Further research is also recommended into the whole area of personal protective clothing and the individual worker's perception of risks to health in the workplace. (+info)
Public health response to an incident of secondary chemical contamination at a beach in the United Kingdom.
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OBJECTIVES: To gather enough data from a large scale investigation involving two health authorities, to assess the possible concentrations and routes of exposure and the consequent health implications. To use the data to decide whether a polluted beach should remain open to the public. In Spring 1997, a chemical incident came to light at a beach on the south coast of England when a local resident reported a sulphurous smell, visible signs of oil, and reduced numbers of fishing bait. The beach was situated adjacent to a former gasworks site and was accessible to the public. The incident was reported to the local authority and was initially investigated by the Environment Agency and the local authority. An Environment Agency report confirmed contamination of the beach with cyanide, ammonia, and polycyclic aromatic hydrocarbons (PAHs) with associated potential health risks. The incident was then referred to the local health authorities for investigation. METHODS: The investigation was carried out in four stages: comprehensive sampling and analysis to identify the extent of contamination, followed by an assessment of risk to health; establishment of a long term monitoring programme to identify any changes in contaminant concentrations; investigation of the effects of the contamination on shellfish; and review of the routine monitoring data and current sampling strategy. RESULTS: The initial investigation confirmed that the beach was contaminated, with the most likely source being the adjacent former gasworks site. The level of contamination was not found to be likely to pose a hazard to users of the beach. However, subsequent investigation of shellfish in the area led to warning signs being erected on the beach to prevent human consumption of mussels contaminated with PAHs. CONCLUSIONS: Several lessons can be learnt from this investigation, which can be applied to incident management more generally: the importance of collaboration and coordination; the need for early involvement of the health authority; and the importance of carrying out appropriate sampling and analysis as soon as possible, to assess the risk to health and the environment. (+info)
Odor-associated health complaints: competing explanatory models.
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Physical symptoms may be reported in workplace and community settings in which odorous airborne chemicals are present. Despite the relative frequency of such reports, clinicians, public health authorities and sensory scientists often experience difficulty interpreting odor-associated symptoms. The approach to interpretation advocated in this review involves: (i) understanding the toxicology of the agent(s) involved (in particular their relative irritant and odorant potencies); (ii) assessing exposure parameters (i.e. concentration and duration). Depending upon exposure concentration, duration and relative irritant and odorant potencies, a variety of pathophysiological mechanisms may be invoked in explaining odor-associated health symptoms. Some of these imputed mechanisms fall under the traditional scope of toxicology and others involve attitudinal and/or behavioral responses to odors. (+info)
Harmonization of cancer and noncancer risk assessment: proceedings of a consensus-building workshop.
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Significant advancements have been made toward the use of all relevant scientific information in health risk assessments. This principle has been set forth in risk-assessment guidance documents of international agencies including those of the World Health Organization's International Programme on Chemical Safety, the U.S. Environmental Protection Agency, and Health Canada. Improving the scientific basis of risk assessment is a leading strategic goal of the Society of Toxicology. In recent years, there has been a plethora of mechanistic research on modes of chemical toxicity that establishes mechanistic links between noncancer responses to toxic agents and subsequent overt manifestations of toxicity such as cancer. The research suggests that differences in approaches to assessing risk of cancer and noncancer toxicity need to be resolved and a common broad paradigm for dose-response assessments developed for all toxicity endpoints. In November 1999, a workshop entitled "Harmonization of Cancer and Noncancer Risk Assessment" was held to discuss the most critical issues involved in developing a more consistent and unified approach to risk assessment for all endpoints. Invited participants from government, industry, and academia discussed focus questions in the areas of mode of action as the basis for harmonization, common levels of adverse effect across toxicities for use in dose-response assessments, and scaling and uncertainty factors. This report summarizes the results of those discussions. There was broad agreement, albeit not unanimous, that current science supports the development of a harmonized set of principles that guide risk assessments for all toxic endpoints. There was an acceptance among the participants that understanding the mode of action of a chemical is ultimately critical for nondefault risk assessments, that common modes of action for different toxicities can be defined, and that our approach to assessing toxicity should be biologically consistent. (+info)