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At least 19 recordsLinked to original sources
PubMed2003

Volcanic ash and respiratory symptoms in children on the island of Montserrat, British West Indies.

BACKGROUND: In July 1995 the volcano on the West Indian island of Montserrat erupted after being inactive for several hundred years. Since then, clouds of ash have been released intermittently from the volcano. Some of this ash is <10 micro m in diameter and therefore respirable. Concerns were raised that the particles might cause respiratory problems. AIMS: To evaluate whether ashfalls had any effect on the respiratory health of children in Montserrat. METHODS: A survey of asthma diagnoses, respiratory symptoms, exercise induced bronchoconstriction (EIB), and current and previous exposure to volcanic ash was carried out in schools in Montserrat during February 1998. RESULTS: Questionnaire information was available for nearly 80% of the 443 children on the school rolls. The prevalence of wheeze symptoms in the previous 12 months was 18% in children aged 12 years and under and 16% in children aged 13 years and over. In children aged 12 and under, the prevalence of wheeze was greater in those who had ever been heavily or moderately exposed to volcanic ash compared with the group who had only ever been exposed to low levels (wheeze in last 12 months: odds ratio (OR) 4.30; wheeze ever: OR 3.45). The prevalence of EIB in 8-12 year olds was about four times higher in those who were currently heavily exposed to volcanic ash (OR 3.85) compared to those currently exposed to low levels. CONCLUSIONS: Volcanic ash emissions adversely affected the respiratory health of Montserrat children. The findings emphasise the need to limit exposures of children to volcanic ash and ensure the appropriate management of respiratory symptoms.

Adolescent↗
PubMed1996

Marked reduction of anemia during pregnancy over a 10-year period in Montserrat.

Anemia during pregnancy is associated with adverse outcomes including maternal and perinatal mortality. However, health education and other public health strategies seeking to reduce its prevalence have usually met with only limited success. The study reported here surveyed anemia of pregnancy on the island of Montserrat in 1980, 1985, and 1990. This involved examination of clinic and hospital records for over 90% of all women giving birth on Montserrat in 1980 and 1985, as well as 80% of those giving birth in 1990. This examination showed a dramatic reduction in the prevalence of anemia at the time of the first prenatal visit (a drop from 82% of the study women in 1980 to 23% in 1985 and 19% in 1990) and also a marked drop at three days postpartum (from 91% in 1980 to 41% in 1985 and 39% in 1990). Logistic regression analyses indicated that after controlling for three possible confounding factors (maternal age, parity, and weeks of gestation at first prenatal visit) the difference between the risk of developing anemia during pregnancy in 1980 as compared to 1985 or 1990 was still highly significant. The reasons for the observed drop in anemia's prevalence during the survey period are not entirely clear, partly because of the retrospective nature of the study. However, better nutrition resulting from improvement in the standard of living on Montserrat during the survey period could have been important, as could changes in health education and food supplementation activities.

Adolescent↗
PubMed2004

Montserrat volcanic ash induces lymph node granuloma and delayed lung inflammation.

OBJECTIVES: A substantial amount of Montserrat volcanic ash, containing up to 24% of cristobalite (w/w), a fibrogenic crystalline silica, has been generated since the first documented eruption in 1995. The bioreactivity of the ash and its two major components: cristobalite and anorthite have been studied in vivo for a year following intratracheal instillation into rats. METHODS: The rats (n=5) were instilled with a sterile vehicle solution (0.15 M NaCl) and/or three doses (1.0, 2.5 or 5.0 mg) of each of the dust, and were sacrificed at 13, 25 or 49 weeks post-instillation for quantitative biochemical and histopathological analyses in the lung and lymph nodes. RESULTS: Cristobalite caused inflammation in the lung and granuloma in the hilar lymph nodes associated with significant size augmentation at 13 weeks post-instillation (P<0.05) and cristobalite (5.0 mg) induced fibrosis in the lung at 49 weeks post-exposure. However, the Montserrat volcanic ash caused inflammation in the lung at 49 weeks post-treatment without any fibrogenic response although the ash (5.0 mg) triggered significant lymph node enlargement without significant changes in the lung at 13 weeks post-treatment (P<0.05). Dose and time independent responses in the anorthite-exposed lung and lymph nodes suggest that a single instillation of 5.0 mg of poorly soluble mineral dust does not induce any change in the lung or lymph nodes. CONCLUSION: The ash produces inflammatory reactions in lymph nodes at 13 weeks post-instillation in rats. These effects are seen much earlier than any inflammatory reaction in the lung. The onset of the lung inflammation is delayed until 49 weeks post-exposure. Despite the high cristobalite content of the ash, there is no evidence of any lung fibrogenic responses.

Aluminum Silicates↗
PubMed2000

In vitro toxicology of respirable Montserrat volcanic ash.

OBJECTIVES: In July 1995 the Soufriere Hills volcano on the island of Montserrat began to erupt. Preliminary reports showed that the ash contained a substantial respirable component and a large percentage of the toxic silica polymorph, cristobalite. In this study the cytotoxicity of three respirable Montserrat volcanic ash (MVA) samples was investigated: M1 from a single explosive event, M2 accumulated ash predominantly derived from pyroclastic flows, and M3 from a single pyroclastic flow. These were compared with the relatively inert dust TiO(2) and the known toxic quartz dust, DQ12. METHODS: Surface area of the particles was measured with the Brunauer, Emmet, and Teller (BET) adsorption method and cristobalite content of MVA was determined by x ray diffraction (XRD). After exposure to particles, the metabolic competence of the epithelial cell line A549 was assessed to determine cytotoxic effects. The ability of the particles to induce sheep blood erythrocyte haemolysis was used to assess surface reactivity. RESULTS: Treatment with either MVA, quartz, or titanium dioxide decreased A549 epithelial cell metabolic competence as measured by ability to reduce 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). On addition of mannitol, the cytotoxic effect was significantly less with M1, quartz, and TiO(2). All MVA samples induced a dose dependent increase in haemolysis, which, although less than the haemolysis induced by quartz, was significantly greater than that induced by TiO(2). Addition of mannitol and superoxide dismutase (SOD) significantly reduced the haemolytic activity only of M1, but not M2 or M3, the samples derived from predominantly pyroclastic flow events. CONCLUSIONS: Neither the cristobalite content nor the surface area of the MVA samples correlated with observed in vitro reactivity. A role for reactive oxygen species could only be shown in the cytotoxicity of M1, which was the only sample derived from a purely explosive event. These results suggest that in general the bioreactivity of MVA samples in vitro is low compared with pure quartz, but that the bioreactivity and mechanisms of biological interaction may vary according to the ash source.

Adsorption↗
PubMed2002

Pulmonary epithelial response in the rat lung to instilled Montserrat respirable dusts and their major mineral components.

BACKGROUND: The Soufriere Hills, a stratovolcano on Montserrat, started erupting in July 1995, producing volcanic ash, both from dome collapse pyroclastic flows and phreatic explosions. The eruptions/ash resuspension result in high concentrations of suspended particulate matter in the atmosphere, which includes cristobalite, a mineral implicated in respiratory disorders. AIMS: To conduct toxicological studies on characterised samples of ash, together with major components of the dust mixture (anorthite, cristobalite), and a bioreactive mineral control (DQ12 quartz). METHODS: Rats were challenged with a single mass (1 mg) dose of particles via intratracheal instillation and groups sacrificed at one, three, and nine weeks. Acute bioreactivity of the particles was assessed by increases in lung permeability and inflammation, changes in epithelial cell markers, and increase in the size of bronchothoracic lymph nodes. RESULTS: Data indicated that respirable ash derived from pyroclastic flows (20.1% cristobalite) or phreatic explosion (8.6% cristobalite) had minimal bioreactivity in the lung. Anorthite showed low bioreactivity, in contrast to pure cristobalite, which showed progressive increases in lung damage. CONCLUSION: Results suggests that either the percentage mass of cristobalite particles present in Montserrat ash was not sufficient as a catalyst in the lung environment, or its surface reactivity was masked by the non-reactive volcanic glass components during the process of ash formation.

Aluminum Silicates↗
PubMed2001

Patrick Browne M. D. (c. 1720-1790), an Irish doctor in the Caribbean: his residence on Saint Croix (1757-1765) and his unpublished accounts of volcanic activity on Montserrat.

Patrick Browne resided on the Caribbean islands of Saint Croix (a Danish possession) and Montserrat (an English possession) during the 1750s and 1760s. He collected and recorded the flora of Saint Croix; some of his notes about the plants of the island have survived and are transcribed. On Montserrat he made observations on the active volcano; the surviving manuscript accounts of the sulphur-rich springs are transcribed.

History, 18th Century↗
PubMed2000

A microbiological survey of Montserrat Island hydrothermal biotopes.

In March 1996, a survey of hydrothermal sites on the island of Montserrat was carried out. Six sites (Galway's Soufrière. Gages Upper and Lower Soufrières, Hot Water Pond, Hot River, and Tar River Soufrière) were mapped and sampled for chemical, ATP, and microbial analyses. The hydrothermal Soufrière sites on the slopes of the active Chances Peak volcano exhibited temperatures up to almost 100 degrees C and were generally either mildly acidic at pH 5-7 or strongly acidic at pH 1.5-3, but with some hot streams and pools of low redox potential at pH 7-8. Hot Water Pond sites, comprising a series of heated pools near the western shoreline of the island. were neutral and saline, consistent with subsurface heating of entrained seawater. Biological activity shown by ATP analyses was greatest in near-neutral pH samples and generally decreased as acidity increased. A variety of heterotrophic and chemolithotrophic thermophilic organisms were isolated or observed in enrichment cultures. Most of the bacteria that were obtained in pure culture were familiar acidophiles and neutrophiles, but novel, iron-oxidizing species of Sulfobacillus were revealed. These species included the first mesophilic iron-oxidizing Sulfobacillus strains to be isolated and a strain with a higher maximum growth temperature (65 degrees C) than the previously described moderately thermophilic Sulfobacillus species.

Adenosine Triphosphate↗
PubMed2000

Microbiology of acidic, geothermal springs of Montserrat: environmental rDNA analysis.

DNA was extracted from water and sediment samples taken from acidic, geothermal pools on the Caribbean island of Montserrat. 16S rRNA genes were amplified by PCR, cloned, sequenced, and examined to indicate some of the organisms that might be significant components of the in situ microbiota. A clone bank representing the lowest temperature pool that was sampled (33 degrees C) was dominated by genes corresponding to two types of acidophiles: Acidiphilium-like mesophilic heterotrophs and thermotolerant Acidithiobacillus caldus. Three clone types with origins in low- and moderate- (48 degrees C) temperature pools corresponded to bacteria that could be involved in metabolism of sulfur compounds: the aerobic A. caldus and putative anaerobic, moderately thermophilic, sulfur-reducing bacteria (from an undescribed genus and from the Desulfurella group). A higher-temperature sample indicated the presence of a Ferroplasma-like organism, distinct from the other strains of these recently recognized acidophilic, iron-oxidizing members of the Euryarchaeota. Acidophilic Archaea from undescribed genera related to Sulfolobus and Acidianus were predicted to dominate the indigenous acidophilic archaeal population at the highest temperatures.

Acetobacteraceae↗
PubMed2003

Surface reactivity of volcanic ash from the eruption of Soufrière Hills volcano, Montserrat, West Indies with implications for health hazards.

The fine-grained character of volcanic ash generated in the long-lived eruption of the Soufrière Hills volcano, Montserrat, West Indies, raises the issue of its possible health hazards. Surface- and free-radical production has been closely linked to bioreactivity of dusts within the lung. In this study, electron paramagnetic resonance (EPR) techniques have been used, for the first time, on volcanic ash to measure the production of radicals from the surface of particles. Results show that concentrations of hydroxyl radicals (HO*) in respirable ash are two to three times higher than a toxic quartz standard. The dome-collapse ash contains cristobalite, a crystalline silica polymorph that may cause adverse health effects. EPR experiments indicate, however, that cristobalite in the ash does not contribute to HO* generation. Our results show that the main cause of reactivity is removable divalent iron (Fe2+), which is present in abundance on the surfaces of the particles and is very reactive in the lung. Our analyses show that fresh ash generates more HO* than weathered ash (which has undergone progressive oxidation and leaching of iron from exposed surfaces), an effect replicated experimentally by incubating fresh ash in dilute acid. HO* production experiments also indicate that iron-rich silicate minerals are responsible for surface reactivity in the Soufrière Hills ash.

Electron Spin Resonance Spectroscopy↗
PubMed1994

Clustering of human T lymphotropic virus type I seropositive in Montserrat, West Indies: evidence for an environmental factor in transmission of the virus.

A community survey of human T cell lymphotropic virus type I (HTLV-I) in Montserrat, West Indies, identified 22 instances in which 2 HTLV-I-seropositive adults lived within 60 m of each other (close pairs), compared with 7.8 expected (P < .001). Five of these close pairs were mother-offspring or husband-wife. The remaining 17 pairs were of unrelated members in separate households. The percentages of male-female (41%), female-female (41%), and male-male (18%) types in these 17 pairs were very similar to those among the 1377 similarly defined pairs in which neither or only 1 member was seropositive, affording no support for extramarital heterosexual activity as an explanation for the clustering observed. Thus, the demography of HTLV-I was not accounted for completely by sexual and mother-to-offspring transmission. The predominance of clustering of unrelated HTLV-I-seropositive individuals in locations with high mosquito infestation raised the possibility of sporadic transmission of HTLV-I by hematophagous insects.

Adolescent↗
PubMed1999

Cristobalite in volcanic ash of the soufriere hills volcano, montserrat, british west indies

Crystalline silica (mostly cristobalite) was produced by vapor-phase crystallization and devitrification in the andesite lava dome of the Soufriere Hills volcano, Montserrat. The sub-10-micrometer fraction of ash generated by pyroclastic flows formed by lava dome collapse contains 10 to 24 weight percent crystalline silica, an enrichment of 2 to 5 relative to the magma caused by selective crushing of the groundmass. The sub-10-micrometer fraction of ash generated by explosive eruptions has much lower contents (3 to 6 percent) of crystalline silica. High levels of cristobalite in respirable ash raise concerns about adverse health effects of long-term human exposure to ash from lava dome eruptions.

Journal Article↗
PubMed2002

Assessment of the exposure of islanders to ash from the Soufriere Hills volcano, Montserrat, British West Indies.

BACKGROUND AND AIMS: The Soufriere Hills volcano, Montserrat, has been erupting since July 1995 and volcanic ash has fallen on the island throughout most of the eruption. The ash contains substantial quantities of respirable particles and unusually large amounts (15-20%) of the crystalline silica mineral, cristobalite. The purpose of the surveys described here, undertaken between December 1996 and April 2000, was to determine levels of personal exposure of islanders to volcanic ash and cristobalite in order to inform advice on the associated risks to health and the measures required to reduce exposure. METHODS: Surveys of personal exposure to respirable dust and cristobalite were undertaken using cyclone samplers. In addition, direct reading instruments (DUSTTRAK) were used to monitor ambient air concentrations of PM(10) at fixed sites and also to provide information about exposures to airborne particles associated with selected activities. RESULTS: Environmental concentrations of airborne ash have been greatest in the areas where the most ash has been deposited and during dry weather. Individual exposure to airborne ash was related to occupation, with the highest exposures among gardeners, cleaners, roadworkers, and police at roadside checkpoints. During 1997 many of these individuals were exposed to concentrations of cristobalite that exceeded the ACGIH recommended occupational exposure limit. Since the population became confined to the north of the island in October 1997, even those in relatively dusty occupations have received exposures to cristobalite well below this limit. CONCLUSIONS: Most of the 4500 people who have remained on island since the eruption began have not been exposed to sufficiently high concentrations of airborne dust for long enough to be at risk of developing silicosis. However, more than a dozen individuals continued to experience frequent high occupational exposures to volcanic ash, some of whom may have had sufficient exposure to crystalline silica to be at risk of developing mild silicosis. If volcanic activity were to deposit further ash over the occupied areas of the island during the coming years, the risks of silicosis will become more substantial.

Adult↗
PubMed1998

Montserrat. Managing health care in a volcanic crisis.

The volcano on Montserrat, after being dormant for over 400 years, has been active for the past two years, last erupting on 27 June, 1997. With the capital, Plymouth, in the unsafe zone, major dislocation of people, facilities and services has occurred. The Health Department is splintered over five sites across an eight mile span and the temporary 30 bed hospital, sited at a primary school, is separated from its Casualty and Out-patient Department and Operating Theatre by 0.25 mile. In order to maintain continuity of care for communities, efforts have been made to keep evacuated clients and their community health workers as close together as possible. The mass emigration has depleted the health services, creating severe stress for those remaining. Elderly relatives have frequently been left behind, necessitating the establishment of special geriatric care facilities to cater to their needs. Increased and continuous health surveillance and mass media education have been integral to the prevention of major disease outbreak--particularly with added challenges to food safety, and management of liquid and solid waste disposal. Cooperation from neighbouring states, particularly Antigua, Barbados and Guadeloupe, as well as from the United Kingdom, has been critical in the management of the continuing crisis.

Aged↗
PubMed2003

The aftermath of a disaster. Recovery following the volcanic eruptions in Montserrat, West Indies.

The people of Montserrat have experienced serious volcanic eruptions since the middle of 1995. These resulted in the evacuation of the capital town Plymouth in 1997. An exclusion zone was declared and two-thirds of the original population of 10,324 migrated abroad. The remainder was left to initiate the recovery process. This paper reviews the action taken to maintain and then restore the health services and the health of the people. The recovery process is now well advanced and is following a characteristic pattern described as the Post Disaster Recovery Scenario. A new hospital was set up in the North of the island and the four remaining clinics refurbished. The health service was restored to a reasonable standard by the end of 2000. A Disaster Preparedness Team is kept on full alert to deal with any emergencies. The disaster caused serious disruption to the health services and to the way of life of the people. It had a number of adverse health effects which included immediate harm to respiratory health followed by other more serious problems such as mental illness, poor nutrition and violence. These were due to the disruption caused by resettlement, overcrowding, breakdown of family life and economic hardship. The lessons learned may be of benefit to countries experiencing similar events in the future.

Adolescent↗
PubMed1982

The presence of Schistosoma mansoni in Montserrat Leeward Islands.

Following the discovery in two villages in Montserrat of five individuals who were passing Schistosoma mansoni ova in their stools, a house to house survey was undertaken in November 1978 to determine the prevalence of the infection. From 158 persons residing in the two villages 137 faecal samples were received. Of these 14% were positive for S. mansoni ova. The enzyme linked immunosorbent assay (ELISA) was performed on finger-prick blood samples collected on chromatography paper. In the ELISA 16% of the 132 persons tested were positive. In comparison with the stool examination, the ELISA showed a 53% sensitivity and a 92% specificity. It was recommended that the individuals passing schistosome eggs should be treated.

Adolescent↗