Sea-dumped chemical weapons: environmental risk, occupational hazard.

INTRODUCTION: Chemical weapons dumped into the ocean for disposal in the twentieth century pose a continuing environmental and human health risk. OBJECTIVE: In this review we discuss locations, quantity, and types of sea-dumped chemical weapons, related environmental concerns, and human encounters with sea-dumped chemical weapons. METHODS: We utilized the Ovid (http://ovidsp.tx.ovid.com) and PubMed (http://www.pubmed.org) search engines to perform MEDLINE searches for the terms 'sea-dumped chemical weapons', 'chemical warfare agents', and 'chemical munitions'. The searches returned 5863 articles. Irrelevant and non-English articles were excluded. A review of the references for these articles yielded additional relevant sources, with a total of 64 peer-reviewed articles cited in this paper. History and geography of chemical weapons dumping at sea: Hundreds of thousands of tons of chemical munitions were disposed off at sea following World War II. European, Russian, Japanese, and United States coasts are the areas most affected worldwide. Several areas in the Baltic and North Seas suffered concentrated large levels of dumping, and these appear to be the world's most studied chemical warfare agent marine dumping areas. Chemical warfare agents: Sulfur mustard, Lewisite, and the nerve agents appear to be the chemical warfare agents most frequently disposed off at sea. Multiple other type of agents including organoarsenicals, blood agents, choking agents, and lacrimators were dumped at sea, although in lesser volumes. Environmental concerns: Numerous geohydrologic variables contribute to the rate of release of chemical agents from their original casings, leading to difficult and inexact modeling of risk of release into seawater. Sulfur mustard and the organoarsenicals are the most environmentally persistent dumped chemical agents. Sulfur mustard in particular has a propensity to form a solid or semi-solid lump with a polymer coating of breakdown products, and can persist in this state on the ocean floor for decades. Rates of solubility and hydrolysis and levels of innate toxicity of a chemical agent are used to predict the risk to the marine environments. The organoarsenicals eventually breakdown into arsenic, and thus present an indefinite timeline for contamination. Generally, studies assaying sediment and water levels of parent chemical agents and breakdown products at dumpsites have found minimal amounts of relevant chemicals, although arsenic levels are typically higher in dumpsites than reference areas. Studies of marine organisms have not shown concerning amounts of chemical agents or breakdown products in tissue, but have shown evidence of chronic toxicity. There is believed to be minimal risk posed by seafood consumption. Microbiota assays of dumpsites are significantly altered in species composition compared to reference sites, which may imply unseen but significant changes to ecosystems of dumpsites. Human health concerns: The major human health risk at this time appears to arise from acute exposure to an agent by either accidental recovery of a chemical weapon on a fishing vessel, or by munitions washed ashore onto beaches. CONCLUSIONS: Improving technology continues to make the deep sea more accessible, thus increasing the risk of disturbing munitions lying on or buried in the seabed. Pipe laying, cable burying, drilling, scuba diving, trawling, and undersea scientific research are the activities posing the most risk. The long-term threat to the benthic habitat via increased arsenic concentrations, shifts in microbiota speciation, and chronic toxicity to vertebrates and invertebrates is not currently understood. The risk to the environment of massive release via disturbance remains a distinct possibility. Terrorist recovery and re-weaponization of chemical agents is a remote possibility.

Rectal administration of N-acetylcysteine in swine: a pilot study.

The purpose of this pilot study was to determine if N-acetylcysteine (NAC) administered via the rectal route in swine is absorbed into the systemic circulation. Fasting swine were anesthetized, intubated, monitored and i.v. access was obtained by femoral cutdown. NAC was administered into the rectal vault (2.0 g/kg) via a balloon-tipped Foley catheter inserted into the animals' rectum. NAC administered via the rectal route resulted in systemic absorption as determined by spectrophotometric methods in 5 of the 7 study animals. This study provides important information regarding the development of a potential alternative route for the administration of NAC.

Material safety data sheet: a useful resource for the emergency physician.

The large number of hazardous chemicals manufactured, transported, and stored in the United States creates the potential for significant toxic exposures to workers in industry today. Emergency physicians are likely to be called upon to evaluate many of these exposures when they occur in the acute setting. In addition to single-patient exposure, significant potential exists for such exposures in the setting of mass casualties. Emergency physicians need a source of readily available information regarding chemical hazards that can be helpful in the diagnosis and treatment of such exposures. The Material Safety Data Sheet (MSDS) is reviewed herein, with special attention given to the sort of information that can be found on the MSDS and how such information can be clinically helpful to emergency physicians. The significant drawbacks and limitations of MSDS documents are also reviewed.

Comparison of deep and shallow endotracheal administration of dionosil in dogs and effect of manual hyperventilation.

The endotracheal route has been used as a second route of choice for administration of emergency drugs for several years; however, the optimal technique for administration of drugs by this route has not been clearly defined. One important aspect of technique involves the question of how distribution to the distal-most endobronchial tree is influenced by initial depth of endotracheally administered drug instillation and use of forced manual hyperventilation. This study demonstrates that depth of instillation of drugs administered by the endotracheal route may not be an important factor in the delivery of medications to absorptive sites in the lung. It appears, however, that forced manual hyperventilation is essential to assure bilateral and optimal distal delivery of endotracheally administered medications.

The use of endotracheal medication in cardiac emergencies.

The endotracheal route for drug administration provides a rapid means of accessing the systemic circulation when intravenous routes cannot be established in emergent situations. This route is relatively free of significant complications and has been documented as being successful numerous times in various clinical settings. Currently, the following drugs have been studied by this route: epinephrine, atropine, lidocaine, naloxone, bretylium, and diazepam. The paper reviews the current state of the art of endotracheal drug administration.

Endotracheal drugs: state of the art.

Endotracheal drug administration has become an acceptable practice in a variety of clinical settings when an intravenous route is not available. Although accepted, its clinical utility in many situations is unproven. Some of the problems that result are presented.

Successful use of emergency transthoracic pacing in bradyasystolic cardiac arrest.

We present the document successful resuscitation of six patients using emergency transthoracic pacing. Two patients were resuscitated from asystole, one had a slow supraventricular bradycardia following head trauma and spinal shock, and three patients had cardiovascular collapse secondary to complete A-V dissociation. One patient developed a non-fatal pericardial tamponade, but there were no cases of pneumothorax. All patients failed to respond to standard medical therapy. We believe that the initially successful resuscitation of these patients was related directly to the pacing procedure. Three patients had underlying pathology that did not allow longterm survival. Three patients were discharged from the hospital without neurologic sequelae. Although emergency transthoracic pacing has a relatively low success rate in bradyasystolic cardiac arrest and may be associated with serious complications, the procedure may be life-saving in selected cases.

Effects of endotracheally administered distilled water and normal saline on the arterial blood gases of dogs.

The effects of endotracheally (ET) administered distilled water (DW) and normal saline solution (NSS) on the arterial blood gases of dogs were compared. When distilled water was administered endotracheally, arterial pH was depressed to 99.36% of baseline values within 5 minutes. When compared to pH changes following ET administration of NSS the depression of pH following DW administration was significant (P less than .05). Following ET injection of DW, arterial PO2 was depressed to 61% of baseline values and remained significantly depressed throughout the experiment. In comparison, following ET NSS administration, PO2 was depressed substantially less, and remained at significantly higher levels for the entire experiment. In dogs, administration of NSS by the ET route produces less detrimental effects on arterial blood gases than does the ET administration of DW. This may have implications for the choice of diluent for human drug administration using the ET route.

Endotracheal administration of atropine sulfate.

Atropine sulfate was successfully administered endotracheally to a 74-year-old patient suffering profound bradycardic cardiovascular collapse. Ninety seconds following endotracheal atropine administration, normal blood pressure and pulse were established. Therapeutic blood levels of atropine were documented following endotracheal administration. The endotracheal route for atropine administration appears to provide an effective alternative route of administration when intravenous access is difficult or impossible to establish rapidly.

Endotracheal naloxone reversal of morphine-induced respiratory depression in rabbits.

In an emergency, intravenous access may be difficult to obtain rapidly. Alternate routes of administration for drugs are, therefore, desirable. Our study was performed to determine if naloxone could be efficacious in reversing morphine-induced respiratory depression in rabbits when administered using the endotracheal route. Our results indicate that naloxone administered in this fashion is effective in reversing morphine-induced respiratory depression in the rabbit. Mean minute ventilation was depressed to greater than half of resting baseline levels using morphine sulfate. Endotracheally administered naloxone reversed this respiratory depression and resulted in a greater than five-fold increase in mean minute ventilation above baseline levels. We concluded that endotracheal naloxone is efficacious in reversing morphine-induced respiratory depression in the rabbit. The endotracheal route may be an effective alternative for naloxone administration in man when rapid intravenous access is not obtainable.

Sledding injuries.

Sixty-one sledding accidents presenting to two Philadelphia-area hospitals during a three-week period were reviewed. The majority of injuries were contusions and abrasions. Eight patients required hospitalization: four had abdominal injury. One patient with multiple trauma was pronounced dead on arrival. The physics of sledding and possible mechanisms of injury are discussed.