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.

The spatial and temporal variations in PM10 mass from six UK homes.

People spend the majority of their time indoors mostly in the domestic environment, where their health may be effected by significant airborne particulate pollution. The indoor/outdoor air quality at six homes in Wales and Cornwall was investigated, based on different locations (urban, suburban, rural) and household characteristics (smokers, non-smokers). The spatial and temporal variations in PM10 mass were monitored for a calendar year, including ambient weather conditions. The activities of individuals within a household were also recorded. Monitoring of PM10 took place inside (kitchen, living room, bedroom) homes, along with concomitant collections outdoors. Samples were subjected to gravimetric analysis to determine PM10 concentrations and examined by scanning electron microscopy to identify the types of particles present on the filters. The results of the study show there are greater masses of PM10 indoors, and that the composition of the indoor PM10 is controlled by outdoor sources, and to a lesser extent by indoor anthropogenic activities, except in the presence of tobacco smokers. The indoor and outdoor PM10 collected was characterised as being a heterogeneous mixture of particles (soot, fibres, sea salt, smelter, gypsum, pollen and fungal spores).

Effects of dietary energy on semen production, fertility, plasma testosterone, and carcass composition of broiler-breeder males in cages.

One hundred-fifty broiler breeder males were raised to 17 wk of age in floor pens using standard procedures. The males were placed in individual cages at 18 wk of age in an environmentally controlled house and fed for recommended BW to 29 wk of age. At 30 wk of age, birds were randomly assigned to one of five dietary treatments. Diets consisted of 10% CP and 1,600, 2,000, 2,400, 2,800, or 3,200 kcal ME/kg feed (Groups 1600, 2000, 2400, 2800, and 3200, respectively). Birds were ejaculated twice weekly; semen characteristics, BW, and serum testosterone (T) were determined every 4 wk. Fertility determinations were made at 38 and 48 wk. At the end of the experiment (60 wk of age), body composition was measured. The percentage of body fat was reduced in Groups 1600, 2000, and 2400. Body weight, percentage of males producing semen, semen weight (SW), total spermatozoa per ejaculate (TS), and T were all reduced in Groups 1600 and 2000; semen concentration (SC) was reduced in Group 1600, compared to the other treatments. Group 2400 had the highest percentage of carcass protein; Groups 1600 and 3200, the lowest percentage. Body weight, percentage of protein, and percentage of fat were quadratically related to dietary energy. The T, SW, SC, and TS were linearly and positively related to the energy level.

Effects of ad libitum and restricted feeding on semen quantity and quality, body composition, and blood chemistry of caged broiler breeder males.

One hundred eighty, 16-wk-old, caged broiler breeder males were randomly assigned to one of three feeding treatments: 1) restricted feeding (RES), breeder-recommended levels minus 25%; 2) control feeding (CON), breeder-recommended levels; 3) full-fed (FF), ad libitum feeding. Each group received the same corn-soybean diet, with 15.5% CP and 2,878 kcal ME/kg feed. The males were ejaculated twice weekly, and BW, semen characteristics, hematocrits (HCT), and serum testosterone (T) were determined every 4 wk. At 17, 35, and 56 wk of age males were killed for body composition determination of percentages of protein, moisture, and fat. The FF males were heavier throughout the experiment than either CON or RES males. The FF group had a higher percentage of males in semen production than CON, which had a higher percentage of males in production than RES. Males of the FF group produced more semen with a higher spermatozoa concentration (SC) than CON, which males had higher spermatozoan concentrations than RES. The FF males had a higher level of T overall than CON or RES males. Hematocrits of FF were higher than those of CON birds, which were higher than those of RES birds. Body compositions were not significantly different among treatments at 17 wk; however, at 35 and 56 wk, FF males had a higher percentage of fat and a lower percentage of protein than birds in the other two groups. Significant positive correlations were found between body fat and the variables HCT, BW, semen weight (SW), and SC. Body weight was positively correlated with SW, and T was correlated with HCT.

Evaluation of bioelectrical impedance for estimation of body composition in 8-week-old broilers.

Bioelectrical measurements (resistance and reactance) were obtained from 35 male and 45 female 8-wk-old broilers using a tetrapolar technique. Body weight, dorsal body length (BL), thigh diameter (TD), and proximate analysis (percentage fat, protein, and moisture) were also ascertained. Twenty birds of each sex were randomly assigned to a calibration group and the remaining birds to a prediction group. Data for birds in the calibration group were used to generate regression equations for estimating whole body composition. Data from birds in the prediction group were collected for possible validation of the calibration equations. Repeatability values for resistance (Re), reactance (Xc), and composition variables were equal to or greater than .78. Coefficients of determination (R2) among percentage body moisture, fat, and protein and body and bioelectrical measurements in males were .41, .36, and .24 (P less than .05), respectively. Percentage moisture in females was predicted by TD2/BL (R2 = .22, P less than .05). Body composition was not adequately predicted by variables measured in this study.

Effects of feeding regimen during early development on body composition, gastrointestinal tract size, and semen quality of broiler breeder cockerels after maturation.

Broiler breeder males were randomly assigned at 3 wk of age to one of three feeding treatments: 1) limited amount daily feeding (LD), 2) skip-a-day feeding (SAD), or 3) limited time feeding (LT). The same diet (16% CP and 3,011 kcal ME/kg) was provided from 3 to 22 wk of age to each treatment. The amount of feed or feeding time was adjusted to maintain recommended BW across treatments. At 22 and 34 wk of age, testes and gastrointestinal (GI) weights and carcass compositions were obtained. From 22 to 34 wk, birds were individually caged and fed ad libitum a breeder diet (15.5% CP and 2,878 kcal ME/kg). Males were ejaculated twice weekly, and BW and semen characteristics were recorded weekly. No significant differences existed among treatments for BW or body composition at 22 wk, but SAD birds had heavier crops and lighter gizzard weights than either LD or LT birds. Sexual maturity occurred 10 days earlier in the LD group than the SAD group; however, the LD group had reduced semen yields and spermatozoa concentrations compared to those in the SAD group. At 34 wk, there were no significant differences among body or GI weights, body moisture, or ash among the treatment groups. Birds in the LD group had heavier livers, greater amounts of body fat, smaller testes, and reduced body protein than those in the other treatments.

Fluorometry of poultry semen: influence of dilution and storage on chicken spermatozoal viability and fertility.

Two experiments were conducted to measure the effects of semen dilution and storage time (0, 1, 2, 3, 4, 24, and 48 h) at 22 C on spermatozoal viability (i.e., membrane permeability to ethidium bromide) and to determine the relationship between concentration of viable spermatozoa inseminated (25, 50, 100, and 200 x 10(6] and fertility. In Experiment 1, percentages of dead spermatozoa remained relatively constant during the 4-h postcollection period but increased significantly (P less than .05) at 24 and 48 h. Sperm viability after 48 h was significantly higher in diluted semen than in undiluted semen. Percent (PF) and duration of fertility (DF) from undiluted semen significantly declined during the 4-h postcollection period compared with fertility of diluted semen. In Experiment 2, both PF and DF improved as the concentration of viable spermatozoa increased. Fertility was not significantly improved by inseminating more than 100 X 10(6) viable spermatozoa. The fertilizing capacity of chicken spermatozoa from undilated semen was affected during storage before membrane permeability to ethidium bromide was altered.

Effects of adding acid or base to the diet on semen of heat-stressed, aging broiler breeder males.

Males were fed breeder basal diet, basal diet + .67 g NaHCO3, + .43 g NH4Cl, or + .86 g NH4Cl/100 g basal and exposed to diurnal cyclic temperatures of 23.9 to 35 C in chambers from 24 to 54 weeks of age. Males fed basal diet + NaHCO3 or .43 g NH4Cl were significantly heavier in body weight by 32 to 39 weeks of age than males on basal diet. Males fed the NaHCO3 diet produced significantly more semen in the first 16 weeks than males on basal diet. No differences were found in percent packed sperm value (PSV), percent dead sperm, or percent abnormal sperm between semen of males fed NaHCO3 diet and basal diet. Spermatozoal motility was significantly higher for semen of males fed NaHCO3 or NH4Cl diets during the 32- to 39-week age period.

The influence of staining techniques and examiners on evaluation of the morphology of fowl spermatozoa.

A total of 53 dwarf Single Comb White Leghorn males from the relaxed selection mating of low and high body weight lines and a randombred control line were used to determine the influence of technique (eosin-nigrosin smears or collection of spermatozoa on membrane filters) and examiner on the assessment of sperm morphology. There were significant (P less than .05) line, technique, examiner, and technique X examiner interactions for sperm abnormalities. Total abnormal spermatozoa were higher in the high line than in the other two lines, and this was associated with increased midpiece defects and twisted spermatozoa. Eosin-nigrosin smears showed almost twice the percentage of abnormal spermatozoa compared to stained membrane filters.

Fluorometry of poultry semen: its application in the determination of viability, enzyme leakage, and fertility.

The accuracy of fluorometry for estimating percentages of dead chicken spermatozoa was investigated by comparing this technique with the eosin-nigrosin differential staining procedure and with glutamic oxaloacetic transaminase (GOT) concentration in seminal plasma. The relationship between percent dead sperm measured by fluorometry and fertility was also examined. The correlation coefficient of percentage of dead spermatozoa determined by fluorometry with eosin-nigrosin counts was highly significant (r = .99; P less than .001). Similarly, the correlation coefficient of GOT activity with percentage of dead spermatozoa was .99 (P less than .001). Percent fertility, fertile egg production, and duration of fertility were negatively correlated with percent dead spermatozoa; 4 = -.55, -.51, and -.44 (P less than .001), respectively.