Asbestos exposure during uncontrolled removal of sprayed-on asbestos.

Asbestos-containing materials in place in buildings, especially sprayed-on asbestos, are still an important health threat. Clearance of these materials has to be operated by specifically trained workers wearing specific individual protection suits after containment of the contaminated area. Good work practices are, however, not always applied. We report the case of two workers hired for ∼1 week to remove sprayed-on amosite asbestos during the remodeling of a former industrial hall. Regulatory protective equipments were not used. A legal action was initiated after disclosure of the working conditions. Medical examinations were performed 18 and 22 months after exposure. Workers denied any other asbestos exposure. Lung function tests and chest computed tomography scans were normal. Very high levels of asbestos fibers and bodies were discovered on mineralogical analysis of bronchoalveolar lavage fluid (BALF) by phase contrast light microscopy and analytical electron microscopy. All fibers were amosite. An extrapolation considering duration of exposure, breathing pattern, and BALF fiber content suggests that the workers were exposed to airborne fiber concentrations in the range from several tens to about a hundred World Health Organization fibers per milliliter air. In conclusion, exposures to historical airborne fiber levels prevailing half a century ago may still occur today when the work regulations are not applied. In these conditions, even very short exposures may result in considerable lung fiber retention in case of amphibole exposure with the subsequent risk for developing asbestos-related diseases. Fiber analysis in BALF is useful to clarify such exposures.

A computer-controlled whole-body inhalation exposure system for the oil dispersant COREXIT EC9500A.

An automated whole-body inhalation exposure system capable of exposing 12 individually housed rats was designed to examine the potential adverse health effects of the oil dispersant COREXIT EC9500A, used extensively during the Deepwater Horizon oil spill. A computer-controlled syringe pump injected the COREXIT EC9500A into an atomizer where droplets and vapor were formed and mixed with diluent air. The aerosolized COREXIT EC9500A was passed into a customized exposure chamber where a calibrated light-scattering instrument estimated the real-time particle mass concentration of the aerosol in the chamber. Software feedback loops controlled the chamber aerosol concentration and pressure throughout each exposure. The particle size distribution of the dispersant aerosol was measured and shown to have a count median aerodynamic diameter of 285 nm with a geometric standard deviation of 1.7. The total chamber concentration (particulate + vapor) was determined using a modification of the acidified methylene blue spectrophotometric assay for anionic surfactants. Tests were conducted to show the effectiveness of closed loop control of chamber concentration and to verify chamber concentration homogeneity. Five automated 5-h animal exposures were performed that produced controlled and consistent COREXIT EC9500A concentrations (27.1 ± 2.9 mg/m(3), mean ± SD).

Neurotoxicity following acute inhalation exposure to the oil dispersant COREXIT EC9500A.

Consequent to the 2010 Deepwater Horizon oil spill in the Gulf of Mexico, there is an emergent concern about the short- and long-term adverse health effects of exposure to crude oil, weathered-oil products, and oil dispersants among the workforce employed to contain and clean up the spill. Oil dispersants typically comprise of a mixture of solvents and surfactants that break down floating oil to micrometer-sized droplets within the water column, thus preventing it from reaching the shorelines. As dispersants are generally sprayed from the air, workers are at risk for exposure primarily via inhalation. Such inhaled fractions might potentially permeate or translocate to the brain via olfactory or systemic circulation, producing central nervous system (CNS) abnormalities. To determine whether oil dispersants pose a neurological risk, male Sprague-Dawley rats were exposed by whole-body inhalation exposure to a model oil dispersant, COREXIT EC9500A (CE; approximately 27 mg/m(3) × 5 h/d × 1 d), and various molecular indices of neural dysfunction were evaluated in discrete brain areas, at 1 or 7 d postexposure. Exposure to CE produced partial loss of olfactory marker protein in the olfactory bulb. CE also reduced tyrosine hydroxylase protein content in the striatum. Further, CE altered the levels of various synaptic and neuronal intermediate filament proteins in specific brain areas. Reactive astrogliosis, as evidenced by increased expression of glial fibrillary acidic protein, was observed in the hippocampus and frontal cortex following exposure to CE. Collectively, these findings are suggestive of disruptions in olfactory signal transduction, axonal function, and synaptic vesicle fusion, events that potentially result in an imbalance in neurotransmitter signaling. Whether such acute molecular aberrations might persist and produce chronic neurological deficits remains to be ascertained.

Acute effects of COREXIT EC9500A on cardiovascular functions in rats.

These studies characterized cardiovascular responses after an acute inhalation exposure to COREXIT EC9500A, the oil dispersant used in the Deepwater Horizon oil spill. Male Sprague-Dawley rats underwent a single 5-h inhalation exposure to COREXIT EC9500A (average exposure level 27.12 mg/m(3)) or air. On d 1 and 7 following the exposure, rats were implanted with indwelling catheters and changes in heart rate and blood pressure were assessed in response to increasing levels of adrenoreceptor agonists. A separate group of rats was euthanized at the same time points, ventral tail arteries were dissected, and vascular tone along with dose-dependent responses to vasoconstricting and dilating factors were assessed in vitro. Agonist-induced dose-dependent increases in heart rate and blood pressure were greater in COREXIT EC9500A-exposed than in air-exposed rats at 1 d but not 7 d after the exposure. COREXIT EC9500A exposure also induced a rise in basal tone and reduced responsiveness of tail arteries to acetylcholine-induced vasodilation at 1 d but not 7 d following the exposure. These findings demonstrate that an acute exposure to COREXIT EC9500A exerts transient effects on cardiovascular and peripheral vascular functions.

Potential immunotoxicological health effects following exposure to COREXIT 9500A during cleanup of the Deepwater Horizon oil spill.

Workers involved in the Deepwater Horizon oil spill cleanup efforts reported acute pulmonary and dermatological adverse health effects. These studies were undertaken to assess the immunotoxicity of COREXIT 9500A, the primary dispersant used in cleanup efforts, as a potential causative agent. COREXIT 9500A and one of its active ingredients, dioctyl sodium sulfosuccinate (DSS), were evaluated using murine models for hypersensitivity and immune suppression, including the local lymph node assay (LLNA), phenotypic analysis of draining lymph node cells (DLN), mouse ear swelling test (MEST), total serum immunoglobulin E (IgE), and the plaque-forming cell (PFC) assay. Dermal exposure to COREXIT 9500A and DSS induced dose-responsive increases in dermal irritation and lymphocyte proliferation. The EC3 values for COREXIT 9500A and DSS were 0.4% and 3.9%, respectively, resulting in a classification of COREXIT 9500A as a potent sensitizer and DSS as a moderate sensitizer. A T-cell-mediated mechanism underlying the LLNA was supported by positive responses in the MEST assay for COREXIT and DSS, indicated by a significant increase in ear swelling 48 h post challenge. There were no marked alterations in total serum IgE or B220+/IgE+ lymph-node cell populations following exposure to COREXIT 9500A. Significant elevations in interferon (IFN)-γ but not interleukin (IL)-4 protein were also observed in stimulated lymph node cells. The absence of increases in IgE and IL-4 in the presence of enhanced lymphocyte proliferation, positive MEST responses, and elevations in IFN-γ suggest a T-cell-mediated mechanism. COREXIT 9500A did not induce immunosuppression in the murine model.

Pulmonary effects after acute inhalation of oil dispersant (COREXIT EC9500A) in rats.

COREXIT EC9500A (COREXIT) was used to disperse crude oil during the 2010 Deepwater Horizon oil spill. While the environmental impact of COREXIT has been examined, the pulmonary effects are unknown. Investigations were undertaken to determine whether inhaled COREXIT elicits airway inflammation, alters pulmonary function or airway reactivity, or exerts pharmacological effects. Male rats were exposed to COREXIT (mean 27 mg/m(3), 5 h). Bronchoalveolar lavage was performed on d 1 and 7 postexposure. Lactate dehydrogenase (LDH) and albumin were measured as indices of lung injury; macrophages, neutrophils, lymphocytes, and eosinophils were quantified to evaluate inflammation; and oxidant production by macrophages and neutrophils was measured. There were no significant effects of COREXIT on LDH, albumin, inflammatory cell levels or oxidant production at either time point. In conscious animals, neither breathing frequency nor specific airway resistance were altered at 1 hr, 1 d and 7 d postexposure. Airway resistance responses to methacholine (MCh) aerosol in anesthetized animals were unaffected at 1 and 7 d postexposure, while dynamic compliance responses were decreased after 1 d but not 7 d. In tracheal strips, in the presence or absence of MCh, low concentrations of COREXIT (0.001% v/v) elicited relaxation; contraction occurred at 0.003-0.1% v/v. In isolated, perfused trachea, intraluminally applied COREXIT produced similar effects but at higher concentrations. COREXIT inhibited neurogenic contractile responses of strips to electrical field stimulation. Our findings suggest that COREXIT inhalation did not initiate lung inflammation, but may transiently increase the difficulty of breathing.

Mercury-contaminated sediments affect amphipod feeding.

A 125-mile reach of the South River, Virginia, was contaminated with mercury during the first half of the 20th century. As increased concentrations of mercury have persisted, researchers have carefully studied its distribution in the river biota and estimated associated risks. The present study evaluated the influence of mercury on feeding rate and uptake by the amphipod Hyalella azteca. The test organisms were exposed for 7 days with leaf discs to reference and contaminated field sediment during the preliminary experiment and additionally to Sedimite (a commercial mercury-sequestering agent) amended sediments during the final experiment. The preliminary experiment demonstrated a decreased feeding rate (approximately 35%) of H. azteca in sediment from a contaminated site relative to sediment from a reference site. The test design of the final experiment took advantage of the knowledge gained in the preliminary experiment by increasing the number of replicates, which decreased the type II error rate. First, the results of the final experiment confirmed the results of the preliminary experiment by again demonstrating differences in the feeding rate of approximately 35% between reference and contaminated sediment. Second, the results indicated a lower feeding rate in reference sediment in the presence of Sedimite. Third, an opposite tendency, although not significant, was apparent for Sedimite-amended contaminated sediment. Thus, Sedimite appears to decrease sediment quality, whereas this conclusion is based on the feeding rate of H. azteca. However, Sedimite and its value as a mercury-sequestering agent requires further evaluation.

The effect of oil spills on workers involved in containment and abatement: the role of the occupational health nurse.

The Deepwater Horizon oil spill is the most recent manmade disaster to challenge occupational health nurses caring for a unique worker population. The effects of oil spills on wildlife, marine life, and the ecosystem are well studied and documented, but the effects on workers who contain and abate such disasters are not. These workers can suffer from a multitude of illnesses and injuries, such as ataxia, migraines, and various lung diseases, which can be a challenge for occupational health nurses.

Influence of waste dump remediation on the levels of mercury in the air.

Mercury concentrations in air were measured at three measuring sites in the vicinity of a waste dump Jakusevec in Zagreb, Croatia over a 4-year period, from the beginning to the end of remediation. Measurements at the beginning of the remediation show that the concentrations of mercury at all three measuring sites were relatively high. Annual mercury mass concentrations in 2001 were between 17 and 445 ng m(-3). Annual mercury averages in 2004 ranged from 8 to 10 ng m(-3). Mercury variations were analysed with regard to the meteorological conditions. The results of this investigation show that in regard to mercury, the remediation was successful.

Negative off-site impacts of ecological restoration: understanding and addressing the conflict.

Ecological restoration is a key component of biological conservation. Nevertheless, unlike protection of existing areas, restoration changes existing land use and can therefore be more controversial. Some restoration projects negatively affect surrounding landowners, creating social constraints to restoration success. Just as negative off-site impacts (i.e., negative externalities) flow from industrial areas to natural areas, restoration projects can generate negative externalities for commercial land uses, such as agriculture. Negative externalities from industry have led to government regulation to prevent human health and environmental impacts. Negative externalities from restoration projects have elicited similar legal constraint on at least one large-scale conservation project, riparian restoration in the Sacramento River Conservation Area. The negative externalities of restoration that are perceived to be the direct result of specific goals, such as endangered species management, are likely to be more contentious than externalities arising from unintended phenomena such as weed invasion. Restoration planners should give equal consideration to off-site characteristics as to on-site characteristics when choosing sites for restoration and designing projects. Efforts to control externalities can lead to off-site ecological benefits.

Health investigations of depleted-uranium clean-up workers.

BACKGROUND: The soil contaminated by depleted uranium (238U) ammunition during the NATO bombing of Serbia and Montenegro was cleaned-up for four months in 2002. A team of 11 clean-up workers (expert members) were medically examined three times: before decontamination as a preliminary medical check-up, immediately after decontamination, and four years after cleaning up contaminated ground. OBJECTIVES: This short report presents investigations and health risk assessments of clean-up workers in radioactive decontamination operations and an assessment of the environmental health perspectives for citizens living in surrounding areas. METHOD: The method of initial health disorders was used, analyzing the most sensitive biological materials, such as blood cells or chromosome damage, DNA strand breaks, radio-toxicological examination of urine. RESULTS: The total number of blood cells did not change, but variations of the relative number (percentage) of cells in the leukocyte formula were observed. The total number of DNA alterations was higher immediately after decontamination than before decontamination. Four years after decontamination the number of DNA alterations had decreased. However, the number of damaged cells (lymphocytes containing chromosome lesions) was higher in both medical examinations, immediately after and four years after decontamination. CONCLUSIONS: Disease or tumours due to 238U did not develop in the group of depleted uranium clean-up workers during the investigation period of four years. Further monitoring of haematological and chromosomal effects and the health condition of workers is necessary.

The effect on ecological systems of remediation to protect human health.

Environmental remediation of contaminated eco-systems reduces stresses to these ecosystems, including stresses caused by the production, use, and storage of weapons of mass destruction. The effects of these various stressors on humans can be reduced by remediation or by blocking the exposure of humans, but blocking the exposure of resident biota is almost impossible. Remediation may involve trade-offs between reducing a minor risk to public health and increasing risks to workers and ecosystems. Remediation practices such as soil removal disrupt ecosystems, which take decades to recover. Without further human disturbances, and with low levels of exposure to stress-ors, ecosystems can recover from physical disruptions and spills. Remediation to remove negligible risk to humans can destroy delicate ecosystems for very little gain in public health.

Impact of electrokinetic remediation on microbial communities within PCP contaminated soil.

Electrokinetic techniques have been used to stimulate the removal of organic pollutants within soil, by directing contaminant migration to where remediation may be more easily achieved. The effect of this and other physical remediation techniques on the health of soil microbial communities has been poorly studied and indeed, largely ignored. This study reports the impact on soil microbial communities during the application of an electric field within ex situ laboratory soil microcosms contaminated with pentachlorophenol (PCP; 100mg kg(-1) oven dry soil). Electrokinetics reduced counts of culturable bacteria and fungi, soil microbial respiration and carbon substrate utilisation, especially close to the acidic anode where PCP accumulated (36d), perhaps exacerbated by the greater toxicity of PCP at lower soil pH. There is little doubt that a better awareness of the interactions between soil electrokinetic processes and microbial communities is key to improving the efficacy and sustainability of this remediation strategy.

Endocrine and immunological parameters in individuals involved in Prestige spill cleanup tasks seven years after the exposure.

In November 2002 the oil tanker Prestige spilled 63,000tonnes of heavy oil off the northwest coast of Spain, impacting more than 1000km of coastline. A general concern led to a huge mobilization of human and technical resources, and more than 300,000 people participated in cleanup activities, which lasted up to 10months. Some endocrine and immunological alterations were reported in Prestige oil exposed subjects for several months. Therefore, the objective of this study was to evaluate if these alterations are still present seven years after the exposure. Fifty-four individuals exposed for at least 2months were compared to 50 matched referents. Prolactin and cortisol plasma concentrations, percentages of lymphocyte subsets (CD3(+), CD4(+), CD8(+), CD19(+), and CD56(+)16(+)), plasma levels of circulating cytokines (interleukin (IL) 2, IL4, IL6, IL10, tumour necrosis factor α, and interferon γ), and serum concentrations of neopterin, tryptophan and kynurenine were determined in peripheral blood samples. Results showed significant differences in exposed individuals vs. referents only in cortisol (increase), kynurenine and %CD16(+)56(+) lymphocytes (both decrease). Time of exposure to the oil or using protective clothes did not influence the results, but effect of using protective mask was observed on neopterin, %CD8(+), CD4(+)/CD8(+) ratio and IL4. Surveillance of the exposed individuals for early detection of possible health problems related to the endocrine or immunological systems is recommended.

Health consequences among subjects involved in Gulf oil spill clean-up activities.

BACKGROUND: Oil spills are known to affect human health through the exposure of inherent hazardous chemicals such as para-phenols and volatile benzene. This study assessed the adverse health effects of the Gulf oil spill exposure in subjects participating in the clean-up activity along the coast of Louisiana. METHODS: This retrospective study included subjects that had been exposed and unexposed to the oil spill and dispersant. Using medical charts, clinical data including white blood cell count, platelets count, hemoglobin, hematocrit, blood urea nitrogen, creatinine, alkaline phosphatase (ALP), aspartate amino transferase (AST), alanine amino transferase (ALT), and somatic symptom complaints by the subjects were reviewed and analyzed. RESULTS: A total of 247 subjects (oil spill exposed, n = 117 and unexposed, n = 130) were included. Hematologic analysis showed that platelet counts (× 10(3) per µL) were significantly decreased in the exposed group compared with those in the group unexposed to the oil spill (252.1 ± 51.8 vs 269.6 ± 77.3, P = .024). Conversely, the hemoglobin (g per dL) and hematocrit (%) levels were significantly increased among oil spill-exposed subjects compared with the unexposed subjects (P = .000). Similarly, oil spill-exposed subjects had significantly higher levels of ALP (76.3 ± 21.3 vs 61.2 ± 26.9 IU/L, P = .000), AST (31.0 ± 26.3 vs 22.8 ± 11.8 IU/L, P = .004), and ALT (34.8 ± 26.6 vs 29.8 ± 27 IU/L, P = .054) compared with the unexposed subjects. CONCLUSION: The results of this study indicate that clean-up workers exposed to the oil spill and dispersant experienced significantly altered blood profiles, liver enzymes, and somatic symptoms.

Water chemistry and nutrient release during the resuspension of FeS-rich sediments in a eutrophic estuarine system.

The objective of this study was to investigate the impact of resuspending FeS-rich benthic sediment on estuarine water chemistry. To address this objective, we conducted (1) a series of laboratory-based sediment resuspension experiments and (2) also monitored changes in surface water composition during field-based sediment resuspension events that were caused by dredging activities in the Peel-Harvey Estuary, Western Australia. Our laboratory resuspension experiments showed that the resuspension of FeS-rich sediments rapidly deoxygenated estuarine water. In contrast, dredging activities in the field did not noticeably lower O(2) concentrations in adjacent surface water. Additionally, while FeS oxidation in the laboratory resuspensions caused measurable decreases in pH, the field pH was unaffected by the dredging event and dissolved trace metal concentrations remained very low throughout the monitoring period. Dissolved ammonium (NH(4)(+)) and inorganic phosphorus (PO(4)-P) were released into the water column during the resuspension of sediments in both the field and laboratory. Following its initial release, PO(4)-P was rapidly removed from solution in the laboratory-based (<1h) and field-based (<100 m from sediment disposal point) investigations. In comparison to PO(4)-P, NH(4)(+) release was observed to be more prolonged over the 2-week period of the laboratory resuspension experiments. However, our field-based observations revealed that elevated NH(4)(+) concentrations were localised to <100 m from the sediment disposal point. This study demonstrates that alongside the emphasis on acidification, deoxygenation and metal release during FeS resuspension, it is important to consider the possibility of nutrient release from disturbed sediments in eutrophic estuaries.

Rational application of chemicals in response to oil spills may reduce environmental damage.

Oil spills, for example those due to tanker collisions and groundings or platform accidents, can have huge adverse impacts on marine systems. The impact of an oil spill at sea depends on a number of factors, such as spill volume, type of oil spilled, weather conditions, and proximity to environmentally, economically, or socially sensitive areas. Oil spilled at sea threatens marine organisms, whole ecosystems, and economic resources in the immediate vicinity, such as fisheries, aquaculture, recreation, and tourism. Adequate response to any oil spill to minimize damage is therefore of great importance. The common response to an oil spill is to remove all visible oil from the water surface, either mechanically or by using chemicals to disperse the oil into the water column to biodegrade. This is not always the most suitable response to an oil spill, as the chemical application itself may also have adverse effects, or no response may be needed. In this article we discuss advantages and disadvantages of using chemical treatments to reduce the impact of an oil spill in relation to the conditions of the spill. The main characteristics of chemical treatment agents are discussed and presented within the context of a basic decision support scheme.