Fumigant-related illnesses: Washington State's five-year experience

Neuropsychological symptoms in workers handling cargo from shipping containers and export logs

PURPOSE

Acute poisonings of workers handling shipping containers by fumigants and other harmful chemicals off-gassed from cargo have been reported but (sub)-chronic neuropsychological effects have not been well studied.

METHODS

This cross-sectional study assessed, using standardised questionnaires, current (past 3-months) neuropsychological symptoms in 274 container handlers, 38 retail workers, 35 fumigators, and 18 log workers, all potentially exposed to fumigants and off-gassed chemicals, and a reference group of 206 construction workers. Prevalence odds ratios (OR), adjusted for age, ethnicity, smoking, alcohol consumption, education, personality traits and BMI, were calculated to assess associations with the total number of symptoms (≥ 3, ≥ 5 or ≥ 10) and specific symptom domains (neurological, psychosomatic, mood, memory/concentration, fatigue, and sleep).

RESULTS

Compared to the reference group, exposed workers were more likely to report ≥ 10 symptoms, statistically significant only for retail workers (OR 6.8, 95% CI 1.9-24.3) who also reported more fatigue (OR 10.7, 95% CI 2.7-42.7). Container handlers with the highest exposure-duration were more likely to report ≥ 10 symptoms, both when compared with reference workers (OR 4.0, 95% CI 1.4-11.7) and with container handlers with shorter exposure duration (OR 7.5, 95% CI 1.7-32.8). The duration of container handling was particularly associated with symptoms in the memory/concentration domain, again both when compared to reference workers (OR 8.8, 95% CI 2.5-31.4) and workers with the lowest exposure-duration (OR 6.8, 95% CI 1.5-30.3).

CONCLUSION

Container handlers may have an increased risk of neuropsychological symptoms, especially in the memory/concentration domain. Retail workers may also be at risk, but this requires confirmation in a larger study.

Identification and evaluation of volatile organic compounds evolved during solarization with almond hull and shell amendments

Biosolarization is a fumigation alternative that combines solarization with organic amendments to suppress pests and pathogens in agricultural soils. The generation of volatile biopesticides in the soil, stemming from biodegradation of carbon-rich amendments, contributes to pest inactivation. The purpose of this study was to (1) profile volatiles that may contribute to pest control under field conditions and (2) measure volatile compounds that may present nuisance or exposure risks for humans near biosolarized fields where larger-scale anaerobic degradation of residues occurs. Biosolarization was performed using prominent agricultural waste products, hulls and shells from several almond varieties as soil amendments. After 8 days of biosolarization, soil samples were analyzed using solid phase microextraction-gas chromatography coupled to mass spectrometry. Volatile fatty acids and ketones made up 85% of biosolarized soil headspace, but terpenes, alcohols, aldehydes, esters, and sulfides were detected as well. Different almond variety residues produced distinct volatile profiles, and nonpareil-amended soils had a much richer and more diverse profile, as well as a fivefold greater VOC abundance, than pollinator-amended soil. Identified volatiles with low US recommended exposure limits were quantified via internal and external standards, including acetic acid, 2-butanone, butanal, hexanal, and phenylethyl alcohol. Across biosolarization treatments, headspace concentrations of selected compounds did not exceed 1 mg/m³. This study demonstrates that almond processing residues recycled into the soil as biosolarization substrates produce a high diversity of bioactive degradation compounds on a field scale, with low potential of non-target risks to humans.Implications: This manuscript has implications for two policy goals in the state of California: to reduce landfill disposal of organic waste, and to reduce emissions from soil fumigants. Almond hulls and shells are an increasing source of organic waste, and novel recycling strategies must be developed. Here, recycling almond residues as soil amendments promoted the rapid formation of VOCs which may act as alternatives to chemical fumigants. Headspace concentrations of potentially deleterious VOCs produced from treated soil were low, on the order of parts per billion. These results will help achieve policy goals by expanding waste usage and fumigation alternatives.

Prognostic Significance of Blood Glucose Levels and Alterations Among Patients with Aluminium Phosphide Poisoning

Objectives

This study aimed to assess the prognostic significance of blood glucose levels and blood glucose alterations (i.e. hyper- or hypoglycaemia) among patients with aluminium phosphide (AlP) poisoning.

Methods

This prospective observational study was conducted at the Postgraduate Institute of Medical Education & Research, Chandigarh, India, between January 2010 and June 2011. All patients presenting to the emergency department with a definitive history of AlP ingestion or symptoms compatible with AlP poisoning were included in the study. Blood glucose levels were recorded at presentation and every six hours thereafter. Alterations in blood glucose levels and other clinical and laboratory variables were subsequently compared between survivors and non-survivors.

Results

A total of 116 patients with AlP poisoning were identified. Of these, 57 patients (49%) survived and 59 patients (51%) died. At presentation, the mean blood glucose levels of survivors and non-survivors were 119.9 ± 35.7 mg/dL and 159.7 ± 92.5 mg/dL, respectively (P <0.001). In comparison to the survivors, non-survivors had significantly higher heart rates, total leukocyte counts, blood glucose level alterations and serum creatinine levels (P <0.050). In addition, systolic blood pressure, Glasgow coma scale scores, arterial blood gas pH and bicarbonate values and duration of hospital stay was significantly lower compared to survivors (P <0.001). However, neither blood glucose levels at admission nor blood glucose alterations correlated independently with mortality in a multivariate analysis.

Conclusion

The role of blood glucose level alterations in predicting patient outcomes in AlP poisoning cases remains inconclusive. Further studies with larger sample sizes are required.

Health risks in international container and bulk cargo transport due to volatile toxic compounds

To ensure the preservation and quality of the goods, physical (i.e. radiation) or chemical pest control is needed. The dark side of such consents may bear health risks in international transport and production sharing. In fact, between 10% and 20% of all containers arriving European harbors were shown to contain volatile toxic substances above the exposure limit values. Possible exposure to these toxic chemicals may occur not only for the applicators but also the receiver by off gassing from products, packing materials or transport units like containers. A number of intoxications, some with lethal outcome, occur not only during the fumigation, but also during freight transport (on bulk carriers and other transport vessels), as well as in the logistic lines during loading and unloading. Risk occupations include dock-workers, seafarers, inspectors, as well as the usually uninformed workers of importing enterprises that unload the products. Bystanders as well as vulnerable consumers may also be at risk. Ongoing studies focus on the release of these toxic volatile substances from various goods. It was shown that the half-lives of the off-gassing process range between minutes and months, depending on the toxic substance, its chemical reactivity, concentration, the temperature, the contaminated matrix (goods and packing materials), and the packing density in the transport units. Regulations on declaration and handling dangerous goods are mostly not followed. It is obvious that this hazardous situation in freight transport urgently requires preventive steps. In order to improve awareness and relevant knowledge there is a need for more comprehensive information on chemical hazards and a broader implementation of the already existing regulations and guidelines, such as those from ILO, IMO, and national authorities. It is also necessary to have regular controls by the authorities on a worldwide scale, which should be followed by sanctions in case of disregarding regulations. Further, fumigated containers must have a warning sign corresponding to international recommendations and national regulations, and freight documents have to indicate any potential hazard during stripping the goods.

Inhalation of phosphine gas following a fire associated with fumigation of processed pistachio nuts

On December 10, 2009, a fumigation stack containing aluminum phosphide became soaked with rain water and caught fire at a pistachio processing plant in Kern County, California. Untrained plant personnel responding to the fire had exposure to pyrolysis by-products, particulates, and extinguisher ingredients. Ten workers taken for medical evaluation had respiratory and nonspecific systemic symptoms consistent with exposure to phosphine gas. Six of the 10 workers had respiratory distress, indicated by chest pain, shortness of breath, elevated respiratory rate, or decreased oxygen saturation. Recommendations are made for the management of similar illnesses and prevention of similar exposures.

Occupational pesticide exposures and respiratory health

Pesticides have been widely used to control pest and pest-related diseases in agriculture, fishery, forestry and the food industry. In this review, we identify a number of respiratory symptoms and diseases that have been associated with occupational pesticide exposures. Impaired lung function has also been observed among people occupationally exposed to pesticides. There was strong evidence for an association between occupational pesticide exposure and asthma, especially in agricultural occupations. In addition, we found suggestive evidence for a link between occupational pesticide exposure and chronic bronchitis or COPD. There was inconclusive evidence for the association between occupational pesticide exposure and lung cancer. Better control of pesticide uses and enforcement of safety behaviors, such as using personal protection equipment (PPE) in the workplace, are critical for reducing the risk of developing pesticide-related symptoms and diseases. Educational training programs focusing on basic safety precautions and proper uses of personal protection equipment (PPE) are possible interventions that could be used to control the respiratory diseases associated with pesticide exposure in occupational setting.

Aluminium phosphide poisoning and oxidative stress: serum biomarker assessment

According to previous animal studies, aluminium phosphides (AlPs) may induce oxidative stress leading to generation of free radicals and alteration in antioxidant defense system. This study was conducted to evaluate the existence and degree of oxidative stress in patients with acute AlP ingestion. A total of 44 acute AlP ingested patients as well as 44 age- and sex-matched controls were included. All patients had acute poisoning symptoms with AlP at the time of presentation and had blood samples analyzed for lipid peroxidation, total antioxidant capacity and total thiol. Our findings showed that there is a significant increase in lipid peroxidation in AlP ingested group along with a reduction in total antioxidant capacity and total thiols groups. These clinical data confirm previous experimental models that showed AlP exposure might significantly augment lipoperoxidative damage with simultaneous alterations in the antioxidant defense system. Hence, our findings might justify use of antioxidants in treatment of acute AlP poisoning which needs to be clarified by additional clinical trials.

Surprises perilous: toxic health hazards for employees unloading fumigated shipping containers

The fumigation of freight containers to protect transported goods from fungal and pest infestation has increased worldwide in the last five years due to international regulations requiring fumigation or heat treatment of wooden packaging material and dunnage. We have found in 2008 that every sixth container and its contents do retain harmful concentrations of various fumigants and chemicals, representing a significant health risk for port and transport workers, customs officials, warehousemen, store employees and consumers. The shipping documents of these containers did not provide any information about the fumigation procedure or the used fumigant. We report here the cases of 26 patients introduced to our outpatient clinic with presumed intoxication to fumigants, or with symptoms due to inhaling the air out of fumigated containers. All patients were examined from 2007 to 2010 according to a standardized comprehensive diagnostic program. We were able to confirm the diagnosis based on typical symptoms and extensive clinical examination; by laboratory analysis we identified ethylene dichloride, methyl bromide, phosphine and methylene chloride. The predominant symptoms were headaches, concentration and memory problems, dizziness and nausea, irritation of the skin and mucous membranes and a reduced ability to do exercise. In addition to the neurological and neuropsychological impairments our analyses verified the development of reactive airways dysfunction syndrome (RADS) in 14 of 26 patients with long lasting symptoms due to their contact with fumigants. Intoxications with fumigants are serious and could be avoided. These systematical explored cases show the sustainable impact for health and socio-economic wellbeing. These findings also emphasize the necessity for international standards on permitted fumigants, appropriate labeling in the shipping documents and handling of fumigated containers.

Blood levels of methemoglobin in patients with aluminum phosphide poisoning and its correlation with patient's outcome

Although methemoglobinemia following aluminum phosphide (AlP) intoxication has been reported, probable effect of blood level of methemoglobin (Met-Hb) on outcome of AlP-poisoned patients has not yet been investigated. This study aimed to evaluate blood levels of methemoglobin in patients with AP intoxication and its correlation with patient's outcome. This prospective study was carried out at the Loghman-Hakim poison hospital from April 2009 to August 2009. All patients aged >12 years who had ingested AlP and were admitted at the hospital were enrolled in the study. Using the co-oximetry, blood Met-Hb level was measured at the time of admission and 24 h later if the patient survived. Forty-eight patients with AlP intoxication including 24 males were evaluated. Mean age of the patients was 25.5±9.5 years. There was significant association between blood level of Met-Hb at the time of admission and mortality (2.4%±7.1% in survivors versus 15.2%±13.5% in non-survivors, P<0.001). The same association was found at the 2nd day of admission (2.9%±8.2% in survivors versus 26.5%±9.9% in non-survivors, P=0.02). The present study found an association between blood level of Met-Hb and mortality in patients with AlP intoxication. Effect of administration of vitamin C and methylene blue on outcome of patients with AlP intoxication should be investigated in future studies.

Absolute kinetics and reaction efficiencies of hydroxyl-radical-induced degradation of methyl isothiocyanate (MITC) in different quality waters

Methyl isothiocyanate (MITC), a toxic and corrosive skin and respiratory irritant, is a common soil fumigant byproduct which has become an atmospheric, aqueous, and soil contaminant. The work described here examines the degradation and potential removal of MITC from contaminated waters via free radical reactions. We have measured the oxidizing hydroxyl radical ((·)OH) reaction rate constant with MITC over a range of temperatures relevant to wastewater treatment conditions, determining a room temperature value of (5.69±0.56) x 10(8)M(-1)s(-1) and a corresponding Arrhenius activation energy of 12.90±0.82 kJ mol(-1). Hydroxyl radical reaction efficiencies with MITC in pure water, an associated matrix of model real-world waters, and a reverse osmosis permeate water have also been determined. While solutions containing these constituents had significantly decreased MITC removal efficiencies (5.5-14.7%) as compared to pure water (54.4±3.4%), relative rate calculation corrections showed that the (·)OH radical efficiencies for solutions containing DOM were the same as in pure water. However, the slightly higher efficiencies for carbonate-containing solutions indicated that some additional MITC degradation occurred from carbonate radical reactions.

Health Profiles of Methyl Bromide Applicators in Greenhouses in Turkey

Introduction: Methyl bromide is a toxic substance that has hazardous effects on human health with acute and chronic exposure. Our previous study showed that methyl bromide applicators frequently use large amounts of methyl bromide haphazardly in greenhouses in the prefectures of Narlidere and Balcova in the Aegean city of Izmir. This study aims to evaluate the health conditions of these workers. Materials and Methods: Our previous study showed that there are 38 methyl bromide applicators in our study area. After the informed consent of methyl bromide applicators was obtained, a questionnaire was used for a survey of demography and symptoms. Each subject was examined before and after application of the compound. Blood and urine samples were collected and stored. Blood samples were analysed for methyl bromide and bromide ion, kidney and liver function tests and lipid profile. Results: The age range of subjects was 19 to 53 years (mean age: 41 ± 8.57). This study showed that methyl bromide applicators use large amounts of methyl bromide disregarding legal regulations and that some of them had non- specific complaints. Subjects had been working as methyl bromide applicators for approximately 9.7 ± 4.15 years. A total of 69.7% of methyl bromide applicators reported that they did not use protective equipment while 33.3% of them had a history of acute methyl bromide intoxication. A statistically significant relationship was found between the usage of protective equipment and the level of blood bromide ion in the blood (P <0.05). Conclusion: Usage of methyl bromide, training, screening and follow-up of applicators must be rigorously controlled in accordance with national legal arrangements and international protocols. Greater efforts are required in the implementation of controls to achieve the targets set by the legal regulations and to ensure continual improvement in the limitation of the risks of this environmental hazard. Key words: Applicator’s health, Chronic exposure, Forensic medicine, Greenhouse workers

Aluminum phosphide-induced esophageal strictures: a new cause of benign esophageal strictures

Fifteen consecutive patients presenting with dysphagia due to aluminum phosphide (AP)-induced esophageal strictures were studied retrospectively to elucidate the natural history of AP-induced esophageal strictures and to evaluate the efficacy of bougie dilation. The median time lag between consumption of AP and occurrence of dysphagia was 3 weeks. All patients had a single stricture and could be dilated using a bougie dilator. Thirteen patients were relieved of dysphagia on a mean (SD) follow-up of 18 (7.3) months. Two patients had recalcitrant strictures and needed needle-knife incision of the stricture followed by balloon dilation. The strictures opened up well in both the patients and they were relieved of dysphagia. AP-induced esophageal stricture is a new cause of benign esophageal stricture. Most patients present with dysphagia around 3 weeks after consumption of AP tablets. A single esophageal stricture is found in these patients. Most strictures respond very well to bougie dilation. However, some of the strictures may be recalcitrant and may require needle-knife incision and balloon dilation.

Hyperglycemia in acute aluminum phosphide poisoning as a potential prognostic factor

Aluminum phosphide (AlP) is a solid fumigant widely used in Iran as a grain preservative. When reacted with water or acids, AIP produces phosphine gas, a mitochondrial poison that interferes with oxidative phosphorylation and protein synthesis. Poisoning by AIP is one of the most important causes of fatal chemical toxicity in Iran. There are few studies in the medical literature addressing prognostic factors associated with AlP poisoning. In this prospective study conducted across a 14-month period commencing on 21st March 2006, we enrolled all patients admitted to the ICU of Loghman-Hakim Hospital Poison Center (Tehran, Iran) with AIP poisoning, no history of diabetes mellitus diagnosed before hospitalization, and normal body mass index. We recorded patient-specific demographic information, blood glucose level on presentation (before treatment), arterial blood gas (ABG) analysis, time elapsed between ingestion and presentation, ingested dose, duration of intensive care admission, and outcome data related to each presentation. We enrolled the group of patients who survived the intoxication as a control group and compared their blood glucose levels with those who died because of AlP poisoning. Data were analyzed by Statistical Product and Service Solutions (SPSS) software (Version 12; Chicago, Ilinois, USA) using logistic regression, Pearson correlation coefficient and Student's t-test. P values of 0.05 or less were considered as the statistical significant levels. Forty-five patients (21 women and 24 men) with acute AlP poisoning were included in the study. The mean age was 27.3 +/- 11.5 years (range: 14-62 years). Thirteen patients survived (29%) and 32 expired (71%). AlP poisoning followed deliberate ingestion in all patients. The time elapsed between ingestion and arrival at the hospital was 3.2 +/- 0.4 h. There was no significant difference between survived and non-survived groups according to age, gender, and time to treatment. However, the difference between mean blood glucose levels in survived (143.4 +/- 13.7 mg/dL) and non-survived (222.6 +/- 20 mg/dL) cases was statistically significant (P = 0.021). There was no significant correlation between blood glucose level and time to treatment, age, gender, pH, HCO3 concentration, and ingested dose. Twenty-three (71.9%) of non-survived and four (30.8%) of survived patients had a blood glucose level greater than 140 mg/dL. After adjusting according to age, gender, ingested dose, pH and HCO3 concentration The odds ratio for hyperglycemia as a risk factor for death was 5.7 (CI of 1.4-23.4). In our study, patients who succumbed to AIP poisoning had significantly higher mean blood glucose levels than those who survived. This correlation of hyperglycemic effect and mortality suggests that it may be useful in guiding risk assessment and treatment of AIP poisoning. Management of hyperglycemia may have a useful role in treatment of these patients by allowing increased entrance of glucose into cells and reducing oxygen consumption.

Neurotoxicity of pesticides

Several pesticides such as organophosphates, carbamates and the organochlorine pesticides directly target nervous tissue as their mechanism of toxicity. In several others, such as the fumigants, the nervous system is affected by toxicological mechanisms that diffusely affect most or all tissues in the body. Both the central and peripheral nervous system are involved in the acute toxidromes of many pesticides resulting in acute short-term effects. There is strong human epidemiological evidence for persistent nervous system damage following acute intoxication with several important pesticide groups such as organophosphates and certain fumigants. However, whether persistent nervous system damage follows chronic low-level exposure to pesticides in adults (particularly organophosphpates), and whether in utero and/or early childhood exposure leads to persistent nervous system damage, is a subject of study at present. Parkinson's Disease, one of the most common chronic central nervous system diseases, has been linked to pesticide exposure in some studies, but other studies have failed to find an association. Several new pesticidal chemicals such as the neo-nicotinoids and fipronil have central nervous system effects, but only case reports are available to date on acute human intoxications with several of these. Little data are yet available on whether long-term effects result from these chemicals. Several ongoing or recently completed studies should add valuable insight into the effects of pesticides on the human nervous system particularly the effect of low-dose, chronic exposure both in adults and children.

Liver histopathology of fatal phosphine poisoning

Two commonly used pesticides in agriculture are phosphides of aluminium and zinc. Both of these metal phosphides act through elaboration of toxic phosphine gas. The poisoning in Iran is mostly oral and suicidal. Phosphine is rapidly absorbed throughout the gastrointestinal tract after ingestion and it is partly carried to the liver by the portal vein. In this study the liver histopathology of fatal poisoning is scrutinized. A descriptive, retrospective study was performed on 38 fatal phosphine poisonings. The slides of liver specimens of the cases were retrieved and studied separately by two pathologists. The poisoning was suicidal in 33 (86.5%) of cases. Portal inflammation was negligible in 37 cases and only in one of the cases, a moderate degree of chronic inflammation accompanied by granuloma formation was observed. Major histopathologic findings were as follows: mild sinusoidal congestion; 12 cases (31.6%), severe sinusoidal congestion; 25 cases (45.8%), central vein congestion; 23 cases (60.5%), centrilobular necrosis; 3 cases (7.9%), hepatocytes nuclear fragmentation; 6 cases (15.8%), sinusoidal clusters of polymorphonuclear leukocytes; 12 cases (31.6%), and mild macrovesicular steatosis; 5 cases (13.2%). Fine isomorphic cytoplasmic vacuoles were observed in 36 cases (94.7%). These vacuoles were distributed uniformly in all hepatic zones in the majority (75%) of cases. This study reveals that the main histopathologic findings of fatal phosphine poisoning in the liver are fine cytoplasmic vacuolization of hepatocytes and sinusoidal congestion.

Control selection and pesticide exposure assessment via GIS in prostate cancer studies

BACKGROUND

Pesticide exposures have recently been linked to prostate cancer, but accurate exposure assessment to date has been challenging. Additionally, historical exposures have rarely been examined. The utility of a geographic information system (GIS)-based model for assessing residential exposure to pesticides is examined in a population-based case-control setting among groups easily recruited as control subjects.

METHODS

Historical pesticide and land-use data were used to generate exposure measures for two distinct pesticides previously linked to prostate cancer risk for control series and prostate cancer cases in three rural California counties. Simple estimates of residential exposures for different exposure periods are compared between case and control groups and the value of complete residential histories is examined.

RESULTS

Residential exposure to methyl bromide based on current address resulted in an overestimation of exposure for distant exposure periods, whereas exposures to organochlorines were similar regardless of availability of historical residence information. A response bias was detected in Medicare controls such that unexposed elderly control subjects were characterized by a higher response rate.

CONCLUSIONS

The frequency and amount of application of pesticides seem to affect the bias introduced into GIS-based exposure assessments. Inclusion of subjects' complete residential histories into the computation of exposure estimates seems to reduce bias from this source, but it may also introduce an additional bias through control self-selection. The use of randomly sampled controls from Medicare and residential parcels listings independent of subject response seems to result in the opportunity for relatively unbiased estimates of pesticide exposures.

Blind and na�ve classi?cation of toxicity by fish chromatophores

Cellular and molecular pathways involved in the ability of animals to change color have been studied previously as biosensors and cytosensors of active and toxic agents, but such studies generally have been limited to just a few standardized agents. Here we describe the performance of cultured chromatophore pigment cells from the fin tissue of Siamese fighting fish as sensors of toxic agents under blind sampling conditions at the September 2002 EILATox-Oregon Workshop. Detection was accomplished by monitoring motor protein-mediated movements of cellular pigment in chromatophores at both the gross population level as well as in singly imaged cells. Pigment responses were recorded both during the exposure of chromatophores to each blind sample as well as afterwards when the cells were examined for after-effects by challenging them with clonidine, an adrenergic drug that induces standardized pigment movements. After recording all results and upon breaking the key to reveal the identities of the toxic agents, it was found that all of the toxic samples in the study had been distinguished accurately from non-toxic controls that were included among the blind samples. Furthermore, it was revealed that most of the toxic agents detected had never before been tested or calibrated against chromatophores, demonstrating that detection can be achieved under naive conditions that have not been optimized for the analysis of any particular toxic agent. Finally, by organizing the results into categories of pigment responses, a binary classification tree was generated that distinguished each toxic agent as having a distinct response pattern from the others. Thus, chromatophore-based cytosensors can discover toxicity in the absence of prior knowledge of the agent in question, and the categories of responses of the cells can be used to distinguish one toxic agent from another.

Modeling of methyl isothiocyanate air concentrations associated with community illnesses following a metam-sodium sprinkler application

BACKGROUND

A series of illnesses occurred in Earlimart, CA on November 13, 1999 following a metam-sodium sprinkler application to a potato field on the southern edge of the town.

METHODS

Case information was obtained from direct interviews, from illness complaints filed with state or county agencies, or from illness reports filed by community physicians for 173 subjects. Air concentrations of the by-product methyl isothiocyanate (MITC) during the episode were estimated based upon the Industrial Source Complex Short-Term (ISC3) air dispersion model, estimates from prior metam-sodium monitoring studies, and data from weather stations in two adjoining communities.

RESULTS

Weather station data indicated that the November 13th incident corresponded with a temperature inversion at approximately 5:00 p.m. and a shift in the direction of prevailing wind from northwest to southeast. On the edge of Earlimart, 1-hr time weighted average (TWA) MITC concentration estimates ranged from 0.5 to 1 ppm. Of the 173 subjects, 170 had MITC-compatible symptoms, including eye or upper respiratory irritation (77.6%), non-specific systemic symptoms (64.7%), and lower respiratory symptoms (20.0%). 78.2% were exposed within 0.5 miles of the northern edge of the treated field where average 1 hr MITC concentrations exceeded the 800 ppb ocular irritation threshold.

CONCLUSIONS

ISC3 modeling is a useful means of evaluating MITC concentrations for illness episodes when industrial hygiene assessment is not possible.

Phosphine exposure from a methamphetamine laboratory investigation

BACKGROUND

Law enforcement personnel may be exposed to a variety of hazardous materials during investigation of clandestine methamphetamine laboratories.

CASE REPORT

A 28-year-old forensic specialist investigating a methamphetamine lab was exposed to phosphine without respiratory protection at approximately 2.7 ppm for 20-30 minutes. Shortly following exposure she developed dizziness, cough, headache, and diarrhea, although initial medical evaluation within 1-2 hours was unremarkable. Pulmonary examination at 4 and 7 days postexposure revealed bilateral rhonchi. The cough was worse with exertion, and persisted despite beta-agonist and steroid inhaler treatment.

CONCLUSIONS

This is apparently the first published case of symptomatic occupational phosphine exposure in a law enforcement officer during investigation of a methamphetamine laboratory. If phosphine exposure is suspected, the possibility of delayed pulmonary toxicity should be recognized.