Marc B. Schenker

Collection and analysis of nicotine as a marker for environmental tobacco smoke

Abstract Nicotine is a potential marker for environmental tobacco smoke (ETS) because it is unique to tobacco smoke and is a major constituent of the smoke. An air sampling method is presented which efficiently collects both particulate and vapor phase nicotine. Two filters are assembled in tandem in a personal sampling cassette. The first filter collects total or size fractional particules and the second is treated with sodium bisulfate to collect vapor phase nicotine and nicotine which has volatilized from the paniculate material collected on the first filler. The nicotine is then desorbed from the filters and analyzed by gas chromatography with nitrogen sensitive detection. The sampling method was evaluated in an environmental chamber under controlled conditions of temperature, humidity, ventilation and smoking rate. It was then employed in a field study of particulate exposures of railroad office workers and railroad mechanics to determine the portion of the particulate exposure attributable to environmental tobacco smoke. The method was found to be efficient and sensitive for the determination of nicotine levels in air.

Exposures and health effects from inorganic agricultural dusts.

Most studies of respiratory disease from dust exposure in the agricultural workplace have focused on allergic diseases caused by inorganic dusts, specifically occupational asthma and hypersensitivity pneumonitis. Exposures to inorganic (mineral) dusts among farmers and farm workers may be substantial. Such exposures are most frequent in dry-climate farming regions. In such locations farming activities that perturb the soil (e.g., plowing, tilling) commonly result in exposures to farm operators of 1-5 mg/m(3) respirable dust and >= 20 mg/m(3) total dust. The composition of inorganic dust in agriculture generally reflects the soil composition. Crystalline silica may represent up to 20% of particles, and silicates represent up to 80%. These very high concentrations of inorganic dust are likely to explain some of the increase in chronic bronchitis reported in many studies of farmers. Pulmonary fibrosis (mixed dust pneumoconiosis) has been reported in agricultural workers, and dust samples from the lungs in these cases reflect the composition of agricultural soils, strongly suggesting an etiologic role for inorganic agricultural dusts. However, the prevalence and clinical severity of these cases are unknown, and many exposures are to mixed organic and inorganic dusts. Epidemiologic studies of farmers in diverse geographic settings also have observed an increase in chronic obstructive pulmonary disease morbidity and mortality. It is plausible that agricultural exposure to inorganic dusts is causally associated with chronic bronchitis, interstitial fibrosis, and chronic obstructive pulmonary disease, but the independent contribution of mineral dusts beyond the effects of organic dusts remains to be determined. ImagesFigure 1Figure 2Figure 3

Personal exposure to dust, endotoxin and crystalline silica in California agriculture.

AIMS The aim of this study was to measure personal exposure to dust, endotoxin and crystalline silica during various agricultural operations in California over a period of one year. METHODS Ten farms were randomly selected in Yolo and Solano counties and workers were invited to wear personal sampling equipment to measure inhalable and respirable dust levels during various operations. The samples were analysed for endotoxin using the Limulus Amebocyte Lysate assay and crystalline silica content using X-ray diffraction. In total 142 inhalable samples and 144 respirable samples were collected. RESULTS The measurements showed considerable difference in exposure levels between various operations, in particular for the inhalable fraction of the dust and the endotoxin. Machine harvesting of tree crops (Geometric mean (GM) = 45.1 mg/m3) and vegetables (GM = 7.9 mg/m3), and cleaning of poultry houses (GM = 6.7 mg/m3) showed the highest inhalable dust levels. Cleaning of poultry houses also showed the highest inhalable endotoxin levels (GM = 1861 EU/m3). Respirable dust levels were generally low, except for machine harvesting of tree crops (GM = 2.8 mg/m3) and vegetables (GM = 0.9 mg/m3). Respirable endotoxin levels were also low. For the inhalable dust fraction, levels were reduced considerably when an enclosed cabin was present. The percentage of crystalline silica was overall higher in the respirable dust samples than the inhalable dust samples. CONCLUSIONS Considerable differences exist in personal exposure levels to dust, endotoxin and crystalline silica during various agricultural operations in California agriculture with some operations showing very high levels.

Costs of occupational injuries in agriculture

Objective. This study was conducted to estimate the costs of job-related injuries in agriculture in the United States for 1992. Methods. The authors reviewed data from national surveys to assess the incidence of fatal and non-fatal farm injuries. Numerical adjustments were made for weaknesses in the most reliable data sets. For example, the Bureau of Labor Statistics (BLS) Annual Survey estimate of non-fatal injuries is adjusted upward by a factor of 4.7 to reflect the BLS undercount of farm injuries. To assess costs, the authors used the human capital method that allocates costs to direct categories such as medical expenses, as well as indirect categories such as lost earnings, lost home production, and lost fringe benefits. Cost data were drawn from the Health Care Financing Administration and the National Council on Compensation Insurance. Results. Eight hundred forty-one (841) deaths and 512,539 non-fatal injuries are estimated for 1992. The non-fatal injuries include 281,896 that led to at least one full day of work loss. Agricultural occupational injuries cost an estimated

Case report : Potential arsenic toxicosis secondary to herbal kelp supplement

4.57 billion (range

Assessment of azinphosmethyl exposure in California peach harvest workers

3.14 billion to

Sharpening the Focus on Acculturative Change: ARSMA-II, Stress, Pregnancy Anxiety, and Infant Birthweight in Recently Immigrated Latinas.

13.99 billion) in 1992. On a per person basis, farming contributes roughly 30% more than the national average to occupational injury costs. Direct costs are estimated to be

Exposure to dust and its particle size distribution in California agriculture.

1.66 billion and indirect costs,

Self-reported stress and reproductive health of female lawyers

2.93 billion. Conclusions. The costs of farm injuries are on a par with the costs of hepatitis C. This high cost is in sharp contrast to the limited public attention and economic resources devoted to prevention and amelioration of farm injuries. Agricultural occupational injuries are an underappreciated contributor to the overall national burden of health and medical costs.

Pneumoconiosis from Agricultural Dust Exposure among Young California Farmworkers

Context Medicinal use of dietary herbal supplements can cause inadvertent arsenic toxicosis. Case Presentation A 54-year-old woman was referred to the University of California, Davis, Occupational Medicine Clinic with a 2-year history of worsening alopecia and memory loss. She also reported having a rash, increasing fatigue, nausea, and vomiting, disabling her to the point where she could no longer work full-time. A thorough exposure history revealed that she took daily kelp supplements. A urine sample showed an arsenic level of 83.6 μg/g creatinine (normal < 50 μg/g creatinine). A sample from her kelp supplements contained 8.5 mg/kg (ppm) arsenic. Within weeks of discontinuing the supplements, her symptoms resolved and arsenic blood and urine levels were undetectable. Discussion To evaluate the extent of arsenic contamination in commercially available kelp, we analyzed nine samples randomly obtained from local health food stores. Eight of the nine samples showed detectable levels of arsenic higher than the Food and Drug Administration tolerance level of 0.5 to 2 ppm for certain food products. None of the supplements contained information regarding the possibility of contamination with arsenic or other heavy metals. The 1994 Dietary Supplement Health and Education Act (DSHEA) has changed the way dietary herbal therapies are marketed and regulated in the United States. Less regulation of dietary herbal therapies will make inadvertent toxicities a more frequent occurrence. Relevance to Clinical Practice Clinicians should be aware of the potential for heavy metal toxicity due to chronic use of dietary herbal supplements. Inquiring about use of dietary supplements is an important element of the medical history.