Gulf War syndrome--a model for the complexity of biological and environmental interaction with human health

Since the end of the Gulf War, tens of thousands of American, Canadian and British soldiers who participated in that war have claimed to be suffering from a variety of incapacitating symptoms which are generally termed as Gulf War Syndrome (GWS). The symptoms are multiple but mainly consist of excessive tiredness, muscle and joint pain, loss of balance, sensory symptoms, neurobehavioural manifestations, diarrhoea, bladder dysfunction, sweating disturbances, and respiratory, gastrointestinal, musculoskeletal and skin manifestations. These veterans have been exposed to a variety of damaging or potentially damaging risk factors including environmental adversities, pesticides such as organophosphate chemicals, skin insect repellents, medical agents such as pyridostigmine bromide (NAPS), possible low-levels of chemical warfare agents, multiple vaccinations in combinations, depleted uranium, and other factors. A large number of basic research findings, clinical epidemiological studies, and case control studies are reviewed to try and link them together to produce a coherent picture and to demonstrate the complexity of the interaction of biological systems, environmental and genetic factors, combinations of drugs and toxins with human health. The findings of these studies so far have demonstrated that many of the previous assumptions made about the 'safety' of certain drugs and toxic substances or vaccines must be radically reviewed. Many of the findings have far reaching implications not only in terms of explanation of what might have gone wrong during the Gulf War, but also have wider implications for many occupational groups who are exposed daily to some of these risk factors. More open-mindedness and much less prejudice are required concerning the basic biology of interactions of the above factors and their effects on cell functions and wider intelligent research is urgently required with high priority. This review highlights the importance of intelligent research for answers for a new phenomenon, and demonstrates the necessity for a combination of this approach with high quality epidemiological research. The reader will notice an emerging clear picture that the majority (if not all) of these advances have been achieved from studies funded by independent or charity organizations rather than by the responsible authorities who are supposed and are duty bound to take on this task.

The diversity of the effects of sulfur mustard gas inhalation on respiratory system 10 years after a single, heavy exposure: analysis of 197 cases

OBJECTIVE

To find out the late pulmonary sequelae of sulfur mustard gas inhalation in 197 veterans, 10 years after their exposure.

DESIGN

Cross-sectional clinical study.

SETTING

University hospital.

PATIENTS

One hundred ninety-seven veterans with a single, heavy exposure to sulfur mustard gas in 1986 and 86 nonexposed veterans as their control group.

INTERVENTIONS

Pulmonary function tests, carbon monoxide diffusion capacity, bronchoscopy, and high-resolution CT of the chest were performed in all patients. Transbronchial lung biopsy was done in 24 suspected cases of pulmonary fibrosis.

RESULTS

Asthma was diagnosed in 21 (10.65%), chronic bronchitis in 116 (58.88%), bronchiectasis in 17 (8.62%), airway narrowing due to searing or granulation tissue in 19 (9.64%), and pulmonary fibrosis in 24 (12.18%) cases. None of these were found among the control group except for a single case of chronic bronchitis.

CONCLUSION

Although the respiratory symptoms of an acute sulfur mustard gas inhalation are usually transient and nonspecific, it can lead to the development of a series of chronic destructive pulmonary sequelae in such cases.

Comparison of a military chemical suit and an industrial usage vapor barrier suit across two thermal environments

This study compared physiological responses to wearing military chemical protective clothing (MPC) and industrial vapor barrier protective clothing (IPC) across two thermal environments to determine the application of the MPC research toward IPC use. Ten males wore each ensemble in a wet bulb globe temperature (WBGT) = 18 and 26 degrees C environment for four test sessions. Each test session consisted of two 30-min work bouts separated by a 30-min recovery period. Each work bout consisted of walking on a treadmill with an oxygen demand of 1.4 L/min for 15 min followed by 7 min of arm curling of 0.9 L/min, followed by 8 min of walking. Work was stopped when either the 30-min time limit was met or a core temperature (Tre) of 38 degrees C was achieved. Variables included sweat rate, heart rate at the end of each work bout, change in (delta) Tre and mean skin temperature (mTsk), and heat stored (Whr). A repeated measures analysis of variance showed no significant difference (p > 0.05) between heart rates at the end of the work bouts between the MPC and IPC. A significant difference was found (p < 0.05) between sweat rates (MPC = 11.5, IPC = 7.4 g/min), delta mTsk, and heat stored, all independent of WBGT. A significant difference (p < 0.05) was also found between delta Tre (MPC = 0.52, IPC = 0.90) in the WBGT = 26 degrees C environment. Results indicate that these two suits elicit similar physiological responses in a cool environment (WBGT = 1 degrees C) but different Tre responses in a hot (WBGT = 26 degrees C) environment. Results show that MPC research can be applied toward IPC settings; however, comparisons between the two should be made with caution, particularly in regard to hot environments.

Pulmonary structural and extracellular matrix alterations in Fischer 344 rats following subchronic phosgene exposure

Phosgene, an acylating agent, is a very potent inducer of pulmonary edema. Subchronic effects of phosgene in laboratory animals are not well characterized. The purpose of the study was to elucidate potential long-term effects on collagen and elastin metabolism during pulmonary injury/recovery and obtain information about the concentration x time (C x T) behavior of low levels of phosgene. Male Fischer 344 rats (60 days old) were exposed either to clean air or phosgene, 6 hr/day: 0.1 ppm (5 days/week), 0.2 ppm (5 days/week), 0.5 ppm (2 days/week), and 1.0 ppm (1 day/week), for 4 or 12 weeks. A group of rats was allowed clean air recovery for 4 weeks after 12 weeks of phosgene exposure. This exposure scenario was designed to provide equal C x T product for all concentrations at one particular time point except for 0.1 ppm (50% C x T). Phosgene exposure for 4 or 12 weeks increased lung to body weight ratio and lung displacement volume in a concentration-dependent manner. The increase in lung displacement volume was significant even at 0.1 ppm phosgene at 4 weeks. Light microscopic level histopathology examination of lung was conducted at 0.0, 0.1, 0.2, and 1.0 ppm phosgene following 4 and 12 and 16 weeks (recovery). Small but clearly apparent terminal bronchiolar thickening and inflammation were evident with 0.1 ppm phosgene at both 4 and 12 weeks. At 0.2 ppm phosgene, terminal bronchiolar thickening and inflammation appeared to be more prominent when compared to the 0.1 ppm group and changes in alveolar parenchyma were minimal. At 1.0 ppm, extensive inflammation and thickening of terminal bronchioles as well as alveolar walls were evident. Concentration rather than C x T seems to drive pathology response. Trichrome staining for collagen at the terminal bronchiolar sites indicated a slight increase at 4 weeks and marked increase at 12 weeks in both 0.2 and 1.0 ppm groups (0.5 ppm was not examined), 1.0 ppm being more intense. Whole-lung prolyl hydroxylase activity and hydroxyproline, taken as an index of collagen synthesis, were increased following 1.0 ppm phosgene exposure at 4 as well as 12 weeks, respectively. Desmosine levels, taken as an index of changes in elastin, were increased in the lung after 4 or 12 weeks in the 1.0 ppm phosgene group. Following 4 weeks of air recovery, lung hydroxyproline was further increased in 0.5 and 1.0 ppm phosgene groups. Lung weight also remained significantly higher than the controls; however, desmosine and lung displacement volume in phosgene-exposed animals were similar to controls. In summary, terminal bronchiolar and lung volume displacement changes occurred at very low phosgene concentrations (0.1 ppm). Phosgene concentration, rather than C x T product appeared to drive toxic responses. The changes induced by phosgene (except of collagen) following 4 weeks were not further amplified at 12 weeks despite continued exposure. Phosgene-induced alterations of matrix were only partially reversible after 4 weeks of clean air exposure.

Pharmacology and toxicology of chemical warfare agents

Toxic chemicals have been used as weapons of war and also as means of terrorist attacks on civilian populations. The main classes of chemical weapons are: a) nerve agents, b) vesicant agents and c) blood agents. If an exposure to nerve agents is anticipated, prophylactic pyridostigmine may be used. Once exposure has occurred, the management strategy is to reduce cholinergic activity through the use of atropine as well as to attempt to regenerate acetylcholinesterase with pralidoxime. Convulsions may be managed using diazepam. Exposure to vesicant agents may be reduced through the use of protective gear, but once exposure has occurred, no specific treatment is available. Treatment remains symptomatic and supportive. Lethal atmospheric concentrations of hydrogen cyanide gas, a blood agent, is seldom achieved except in enclosed spaces. Sub-lethal exposure to hydrogen cyanide may be managed using sodium nitrite, sodium thiosulphate and VitB12.

[Epidemiology of lung cancer in former poison-gas workers and molecular approaches to lung cancer]

Former poison-gas workers were found to have a high incidence of respiratory neoplasia. The development of cancer in these people could be suppressed by the administration of Nocardia rubra cell-wall skeleton. Efforts to improve the prevention and treatment of lung cancer include studies of telomerase activity and genetic aberrations in samples from patients with cancer, monitoring of the concentration of anti-cancer drugs, and studies of the feasibility of gene therapy with adenovirus vectors.

Toxicology and pharmacology of the chemical warfare agent sulfur mustard

There have been reports of chemical attacks in which sulfur mustard might have been used (a) on Iranian soldiers and civilians during the Gulf War in 1984 and 1985 and (b) in an Iraqi chemical attack on the Iranian-occupied village of Halbja in 1988, resulting in many civilian casualties. Heavy use of chemical warfare in Afghanistan by the Soviet military is a recent innovation in military tactics that has been highly successful and may ensure further use of chemical agents in future military conflicts and terrorist attacks as a profitable adjunct to conventional military arms. Mustard is a poisonous chemical agent that exerts a local action on the eyes, skin, and respiratory tissue, with subsequent systemic action on the nervous, cardiac, and digestive systems in humans and laboratory animals, causing lacrimation, malaise, anorexia, salivation, respiratory distress, vomiting, hyperexcitability, and cardiac distress. Under extreme circumstances, dependent upon the dose and length of exposure to the agent, necrosis of the skin and mucous membranes of the respiratory system, bronchitis, bronchopneumonia, intestinal lesions, hemoconcentration, leucopenia, convulsions with systemic distress, and death occur. Severe mustard poisoning in humans is associated with systemic injury, which is manifested as headache, epigastric distresses, anorexia, diarrhea, and cachexia and is usually observed at mustard doses of 1000 mg/min/m3 with damage to hematopoietic tissues and progressive leucopenia. Sulfur mustard is a cell poison that causes disruption and impairment of a variety of cellular activities that are dependent upon a very specific integral relationship. These cytotoxic effects are manifested in widespread metabolic disturbances whose variable characteristics are observed in enzymatic deficiencies, vesicant action, abnormal mitotic activity and cell division, bone marrow disruption, disturbances in hematopoietic activity, and systemic poisoning. Indeed, mustard gas readily combines with various components of the cell such as amino acids, amines, and proteins. Although evidence of an association between lung cancer and mustard gas encountered on the battlefields of World War I is at best suggestive if not problematical (Case and Lea, 1955; Beebe, 1960; Norman, 1975), the epidemiological data accumulated from the poison gas factories in Japan (Yamada et al., 1953; Wada et al., 1968; Inada et al., 1978; Shigenobu, 1980; Nishimoto et al., 1983; Hirono et al., 1984; Takuoka et al., 1986), in Germany (Weiss, 1958; Hellmann, 1970a; Weiss and Weiss, 1975; Klehr, 1984) and in England (Manning et al., 1981; Easton et al., 1988) are substantial (International Agency for Research on Cancer, 1975). Unfortunately, attempts to seek confirmatory and substantial evidence in laboratory animals such as mice (Boyland and Horning, 1949; Heston, 1950; Heston, 1953a; McNamara et al., 1975) and rats (Griffin et al., 1951; McNamara et al., 1975; Sasser et al., 1996) have not been consistent. Sulfur mustard has been shown to be mutagenic in a variety of different species using many different laboratory techniques from fruit flies, microorganisms and mammalian cell cultures (Fox and Scott, 1980). Evidence is slowly accumulating from human data (Hellmann, 1970a; Lohs, 1975; Wulf et al., 1985). Evidence for the teratogenicity of mustard has been negative in assessment of fetotoxicity and adverse effects of mustard on the reproductive potential of both human and animal studies. Indeed, investigations of women adversely affected by mustard are minimal because most of the studies have been performed on former men employees of poison gas factories and have been negative or questionable. We have recently emphasized the need to assess the affect of a suspected teratogen on maternal toxicity in laboratory animals before any conclusions can be made.(ABSTRACT TRUNCATED)

Former poison gas workers and cancer: incidence and inhibition of tumor formation by treatment with biological response modifier N-CWS

Mustard gas is known to have mutagenic and carcinogenic effects on animal and human cells. In this report, 1,632 male Japanese who worked in poison gas factories at some time between the years 1927 and 1945 were studied to determine comparative risk for development of cancer, the reference population being data on Japanese males overall. The standardized mortality ratio (SMR) for lung cancer in workers directly and indirectly involved in the production of mustard gas was significantly elevated. In addition, SMR for lung cancer in worker who had worked for more than 5 years was also significantly elevated. Thus, poison gas workers who had engaged in the production of mustard gas or related work for more than 5 years are a high-risk group for lung cancer. Under the cancer preventive program, Nocardia rubra cell-wall skeleton (N-CWS) was administered to 146 former poison gas workers. During a 4.5 year observation period, development of cancers was found in 7 treated workers and 17 untreated controls. After elimination of the influence of smoking level, a significant suppression of development of cancers was noted in the N-CWS-treated workers as compared to the untreated controls. Although the molecular mechanisms of carcinogenesis in former poison gas workers remains unclear, our study proposes the possible effect of biological response modifiers in the prevention of cancer development in high-risk human subjects.

Post-traumatic stress disorder among World War II mustard gas test participants

Open-minded and structured interviews were conducted to assess post-traumatic stress disorder (PTSD) and other psychosocial outcomes among 24 men who had participated in the military's mustard gas testing program during World War II. Most men had volunteered (92%) and had participated in chamber tests (96%). During the tests, few (22%) understood the danger involved. The majority (67%) were ordered to refrain from discussing their participation with anyone. Most men (83%) experienced physical symptoms subsequent to the test. At present, the men were less psychologically and physically healthy than expected for men of similar age. The current prevalence of PTSD due to the mustard gas was 17%. The current prevalence of subdiagnostic mustard-gas-related PTSD was 25%. Lifetime estimates for full and subdiagnostic PTSD was 17 and 33%, respectively. The only mustard gas experience that predicted lifetime full or subdiagnostic PTSD was the number of exposures to the gas.

Acute lung injury after phosgene inhalation

Phosgene (COCl2) is a colorless oxidant gas which is heavier than air and the lethal exposure dose (LC50) in humans is 500 ppm/min. This gas was originally manufactured as an agent for chemical warfare during World War I and there had been a great deal of studies on phosgene poisoning during the early years of industrial use. It is still widely used in the synthesis of chemicals and plastics. In the modern era, however, phosgene poisoning is relatively uncommon except in accidental exposures. In Korea, there has been no report about lung injury from phosgene inhalation. We present a clinical experience with six patients accidentally exposed to phosgene.

Congenital malformations in the progenies of Iranian chemical victims

The incidence of congenital malformations among the progenies of the Iranian chemical victims were studied. A higher incidence of abnormalities were found among survivors' offspring of Iranian gas victims. Parental exposure to chemical weapons may be associated with an increased risk for some congenital malformations.

The surgical management in war of penetrating wounds contaminated with chemical warfare agents

Military surgeons in a future conflict may face the problem of wounds contaminated with chemical warfare (CW) agents. No useful guidelines for this eventuality exist-nor any assessment of the specific CW risk to such casualties or to the surgical teams operating on them. The principal hazard to surgeons is direct contact with contaminated clothing in the wound. Practices are recommended to reduce this threat significantly. Thorough wound excision augmented by lavage with a specific proprietary hypochlorite solution will provide effective wound decontamination without producing unacceptable tissue damage. The vapour hazard at surgery is very low-respirators are unnecessary but goggles or glasses should be worn to prevent conjunctival splashes of potentially contaminated body fluids.

Cholinesterase activity in postmortem blood as a screening test for organophosphate/chemical weapon exposure

This study was undertaken to determine whether postmortem blood cholinesterase activity could be used as a screening test for exposure to nerve agents. Whole blood cholinesterase activity at 25 degrees C was analyzed for a one week period in order to simulate the battle field collection problems of: hemolyzed blood samples, delayed recovery of the specimen, and unrefrigerated transfer to the testing facility. A total of 53 nonpreserved post-mortem whole blood specimens were analyzed in triplicate for cholinesterase activity by the delta pH method of Michel. There was a negligible loss of cholinesterase activity by the seventh day of the study. The enzyme activities of the specimens had a mean value (range) of 0.48 (0.20 to 0.74) initially and 0.45 (0.07 to 0.70) pH units after one week. Whole blood from five healthy adults remained essentially unchanged during this period, with an initial value 0.59 (0.52 to 0.67) and a final value of 0.52 (0.46 to 0.62) pH units. To compare postmortem and simulated nerve agent values, aliquots from 18 of the original 53 postmortem specimens were frozen during day one of the study, thawed on day seven and a cholinesterase inhibitor added. These specimens were then analyzed with the other specimens. All values from inhibited specimens were essentially zero (0.0 to 0.01) pH units compared to a range of 0.07 to 0.61 pH units for matched, uninhibited, day seven postmortem specimens. Fifteen actual nonpreserved specimens from the battlefield were analyzed as verification of screen performance. Their results fell within the uninhibited postmortem range above.(ABSTRACT TRUNCATED AT 250 WORDS)

Eighty years of the threat and use of chemical warfare: the medical-organizational challenge

The threat of using chemical warfare (CW) by countries ruled by dictators and totalitarian governments still exists despite the Geneva Convention of 1925 that prohibited the use of CW. This situation forces nations and their armed forces to be in a state of preparedness in the event of a CW attack. A CW attack on an unprotected civilian population in a dense urban area can cause numerous casualities and become a mass disaster. However, this danger may be significantly reduced by: a) providing collective and individual protective measures, b) training the population in the use of protective measures, and c) early warning to provide sufficient lead time to use the various components of protection. Coping with a nonconventional warfare threat requires an innovative approach in the organization of the health care delivery system so as to maximize the number of survivors. The fact that the population is protected may deter the enemy from using CW since the potential destructive impact of CW is neutralized or at least reduced.

Mortality and morbidity among Army Chemical Corps Vietnam veterans: a preliminary report

Nearly 1,000 men serving in Army Chemical Corps units in Vietnam between 1965 and 1971 were responsible for the mixing and application of herbicides, riot control substances, and burning agents. Information on Vietnam service was obtained from military records of 94% of this cohort. Follow-up for vital status on December 31, 1987, was conducted using Department of Veterans Affairs (VA), military, National Death Index, U.S. Internal Revenue Service, and Social Security Administration records. Cause-specific observed numbers of deaths among the 894 men included in the study group were compared with the numbers expected based on rates for U.S. men, adjusting for race, age, and calendar period. Fifty-three deaths from all causes were observed during the study period, compared to 48.8 expected (SMR = 1.09). There were statistically significant excesses of digestive disease deaths (SMR = 2.98), primarily due to cirrhosis, and from motor vehicle accidents (SMR = 2.00). Two deaths were observed from leukemia (0.5 expected) and two from brain cancer (0.4 expected). A total of 257 of the study subjects had received VA inpatient care or Agent Orange registry medical examinations during the study period. Two of these subjects had confirmed diagnoses of Hodgkin's disease (expected = 0.7) and one of hairy cell leukemia. Because of the small study group size and the lack of specificity of information regarding their exposures, these results cannot be attributed to any single chemical agent.

[Damage caused by chemical warfare agents]

A survey of potential chemical warfare agents of the NATO and of the injuries caused by them is given. After a short characterization of the course and the symptomatology of the injuries the paper indicates the possibilities of giving medical aid at war and refers to the tasks which are derived from this for the education and continued professional training of medical staff.

[Status and trends of development of chemical warfare agents of imperialist countries]

At present the dangerous experiment is made by the USA and their NATO-partners to force the armament also in the field of military chemistry. On the basis of the structural warfare agents of the NATO, which are produced and stored in large quantities and are immediately applicable, with high intensity is worked at the further development of chemical warfare agents. Here the development of new action means for the realisation of an equivalence of the effect between warfare agent and action means is the central point. The principles of action for chemical warfare agents incorporate into the strategy of the imperialistic army commands in a possible war, which is based on the cooperation of mass extermination and conventional arms.