Elements in human placentae in Jamaica / Elementos en las placentas humanas en Jamaica

AIM: To investigate the relationships, if any, between elemental content of the placenta with age of mother, birthweight and the Apgar scores of a neonate. METHODS: Placental samples were collected, stored at -20ºC and then dried and analysed using neutron activation with the SLOWPOKE II reactor at the International Centre for Environmental and Nuclear Sciences (ICENS). A questionnaire was administered at the time of delivery to determine the level of fish consumption, numbers of dental amalgam fillings and use of cough syrups. Placental concentrations of bromine, calcium, chlorine, iron, mercury, potassium, rubidium, selenium, sodium and zinc were determined. RESULTS: The placentae of 52 Jamaican mothers with a mean age 29 years (range 18-42 years) delivering singleton neonates with a mean birthweight of 3.1 kg (1.3 - 5.5 kg) at term were collected. With the exception of iron and bromine, all results for elemental determinations are very similar to those found elsewhere. Correlation was observed for Apgar 2 (5 minutes), calcium and zinc with birthweight, with p-values of 0.002, 0.007 and 0.07, respectively. Negative correlation was observed for the Apgar 2 and potassium (p = 0.056) and age of mother at birth and bromine (p = 0.02). The mercury concentration in the measured placentae (7.29 ±9.1 µg/kg w/w) was slightly lower than the mean concentration found in the literature (8 µg/kg w/w). Approximately 93% of the measured placentae in this study are below the derived placentae upper limit of 22 µg/kg. Of the 7% above the upper limit none exceeded the conservative estimated limit of 115 /µg/kg at which neural developmental problems start. CONCLUSION: The significant associations noted are of unknown clinical relevance and need further study.

OBJETIVO: Investigar las relaciones que pudieran existir entre el contenido elemental de la placenta y la edad de la madre, el peso al nacer, y la puntuación Apgar del neonato. MÉTODOS: Muestras de placenta fueron recogidas, almacenadas a -20ºC y entonces secadas y analizadas usando la activación neutrónica con el reactor SLOWPOKE II del Centro Internacional de Ciencias Medioambientales y Nucleares (ICENS). A la hora del parto se aplicó una encuesta para determinar el nivel de consumo de pescado, el número de amalgamas dentales y el uso de jarabes para la tos. Se determinaron las concentraciones placentales de bromo, calcio, cloro, hierro, mercurio, potasio, rubidio, selenio, sodio y cinc. RESULTADOS: Se recogieron las placentas de 52 madres jamaicanas con una edad promedio de 29 años (rango 18-42 años) que parieron neonatos únicos con un peso promedio de 3.1 kg (1.3-5.5 kg) a término. Con la excepción del hierro y el bromo, todos los resultados para las determinaciones elementales son muy similares a los hallados en otras partes. Se observó una correlación de Apgar 2 (5 minutos), el calcio y el cinc con el peso al nacer, los valores p de 0.002, 0.007 y 0.07 respectivamente. Se observó una correlación negativa de Apgar 2 y el potasio (p = 0.056) y la edad de la madre a la hora del alumbramiento, con el bromo (p = 0.02). La concentración de mercurio en las placentas medidas (7.29 ± 9.1 w/w de µg/kg) fue ligeramente más baja que la concentración promedio hallada en la literatura (8 µg/kg w/w). Aproximadamente 93% de las placentas evaluadas en este estudio están por debajo del límite superior de 22 µg/kg. Del 7% por encima del límite superior, ninguna excedió el límite conservador estimado de 115 µg/kg en el cual comienzan los problemas del desarrollo neural. CONCLUSIÓN: Se desconoce la importancia clínica de las asociaciones significativas observadas y se requiere más estudio.

Elements in human placentae in Jamaica.

AIM: To investigate the relationships, if any, between elemental content of the placenta with age of mother birthweight and the Apgar scores of a neonate. METHODS: Placental samples were collected, stored at -20 degrees C and then dried and analysed using neutron activation with the SLOWPOKE II reactor at the International Centre for Environmental and Nuclear Sciences (ICENS). A questionnaire was administered at the time of delivery to determine the level of fish consumption, numbers of dental amalgam fillings and use of cough syrups. Placental concentrations of bromine, calcium, chlorine, iron, mercury, potassium, rubidium, selenium, sodium and zinc were determined. RESULTS: The placentae of 52 Jamaican mothers with a mean age 29 years (range 18-42 years) delivering singleton neonates with a mean birthweight of 3.1 kg (1.3-5.5 kg) at term were collected. With the exception of iron and bromine, all results for elemental determinations are very similar to those found elsewhere. Correlation was observed for Apgar 2 (5 minutes), calcium and zinc with birthweight, with p-values of 0.002, 0.007 and 0.07, respectively. Negative correlation was observed for the Apgar 2 and potassium (p = 0.056) and age of mother at birth and bromine (p = 0.02). The mercury concentration in the measured placentae (7.29 +/- 9.1 microg/kg w/w) was slightly lower than the mean concentration found in the literature (8 microg/kg w/w). Approximately 93% of the measured placentae in this study are below the derived placentae upper limit of 22 microg/kg. Of the 7% above the upper limit none exceeded the conservative estimated limit of 115 microg/kg at which neural developmental problems start. CONCLUSION: The significant associations noted are of unknown clinical relevance and need further study.

Acute lead poisoning associated with backyard lead smelting in Jamaica / Envenenamiento agudo con plomo asociado con la fundición casera de plomo en Jamaica

Long-term backyard smelting of lead in a district known as Mona Commons, Kingston, Jamaica, has produced lead burdens as high as 30 000 mg/kg in soils near to the smelter, and indoor dust loadings of 373 microg/f2 in the residents' home. The blood lead levels (BPb) of 107 children from the district were in the range 2.2-202 microg/dL. Fifty-nine per cent of these had BPb levels above 10 microg/dL and the population mean was an unacceptably high 25.1 microg/dL. The highest levels were observed for five siblings, two of whom presented with lead encephalopathy. This severe chronic exposure to lead was exacerbated by a significant history of pica, and chronic nutritional anaemia. Chelation therapy significantly reduced the BPb levels but due to lead storage in other organs, the values after several months were still higher than desirable. This study emphasizes the importance of reducing the exposure of children to lead.

Acute lead poisoning associated with backyard lead smelting in Jamaica.

Long-term backyard smelting of lead in a district known as Mona Commons, Kingston, Jamaica, has produced lead burdens as high as 30 000 mg/kg in soils near to the smelter, and indoor dust loadings of 373 microg/f2 in the residents' home. The blood lead levels (BPb) of 107 children from the district were in the range 2.2-202 microg/dL. Fifty-nine per cent of these had BPb levels above 10 microg/dL and the population mean was an unacceptably high 25.1 microg/dL. The highest levels were observed for five siblings, two of whom presented with lead encephalopathy. This severe chronic exposure to lead was exacerbated by a significant history of pica, and chronic nutritional anaemia. Chelation therapy significantly reduced the BPb levels but due to lead storage in other organs, the values after several months were still higher than desirable. This study emphasizes the importance of reducing the exposure of children to lead.

In situ gamma spectroscopy measurement of 41Ar during neutron activation analysis with the SLOWPOKE II reactor in Jamaica.

In situ gamma spectroscopy was used to measure 41Ar released into the laboratory due to the activation of air in the irradiation tubes of SLOWPOKE reactor during routine neutron activation analysis. The data obtained were used to predict the 41Ar distribution in the laboratory for various operating conditions of the reactor. The dose received by the analyst from the immersion in 41Ar was calculated to be 2.36 microSv gamma(-1), which is approximately 1% of the normal background exposure.

Trace elements in Jamaican tobacco.

The concentrations of 28 elements, in hand-made cigars, "rope" tobacco and freshly picked tobacco leaves from the parish of Manchester in central Jamaica, were compared with locally packaged and imported cigarettes and cigars. Except for chromium and vanadium, which are lower in the imported products, the elemental concentrations of all the brands sold in Jamaica are rather similar. The means for aluminium, cadmium, caesium, cerium, chromium, iron, thorium, uranium, vanadium and zinc for the Manchester material exceed the maximum values of the other tobaccos. The significant concentrations of heavy metals, and especially cadmium, which is about 50 times that of commercial cigarettes, reflect the known high concentrations in the soils in the region. This tobacco is not filtered and the smoke contains 50% of the cadmium. This, and the concentrations of radioactive elements, may indicate an additional health risk compared with commercial cigarettes. A study of three samples of marijuana indicates a similar level of risk from heavy metals.

Blood lead levels in children in Jamaican basic schools.

Blood lead levels (BLL) for 285 children, three to six years old, from seven basic schools located in known areas of anthropogenic pollution, and in urban and rural areas are reported. The samples were obtained by the finger-prick method and analyzed for lead by anodic stripping voltammetry. The majority of the children had blood lead levels below the now accepted limit of 10 micrograms dL-1 and there was no indication of cases that would represent medical emergencies. The present results show considerable improvement in the BLLs of children living in contaminated sites indicating the effectiveness of the previous remediation steps. Follow-up intervention work is in progress for cases of blood lead levels in excess of the recommended limit.

Blood lead levels in children in Jamaican basic schools

Blood lead levels (BLL) for 285 children, three to six years old, from seven basic schools located in known areas of anthropogenic pollution, and in urban and rural areas are reported. The samples were obtained by the finger-prick method and analyzed for lead by anodic stripping voltammetry. The majority of the children had blood lead levels below the now accepted limit of 10 micrograms dL-1 and there was no indication of cases that would represent medical emergencies. The present results show considerable improvement in the BLLs of children living in contaminated sites indicating the effectiveness of the previous remediation steps. Follow-up intervention work is in progress for cases of blood lead levels in excess of the recommended limit

Trace elements in Jamaican tobacco

The concentrations of 28 elements, in hand-made cigars, [quot ]rope[quot ] tobacco and freshly picked tobacco leaves from the parish of Manchester in central Jamaica, were compared with locally packaged and imported cigarettes and cigars. Except for chromium and vanadium, which are lower in the imported products, the elemental concentrations of all the brands sold in Jamaica are rather similar. The means for aluminium, cadmium, caesium, cerium, chromium, iron, thorium, uranium, vanadium and zinc for the Manchester material exceed the maximum values of the other tobaccos. The significant concentrations of heavy metals, and especially cadmium, which is about 50 times that of commercial cigarettes, reflect the known high concentrations in the soils in the region. This tobacco is not filtered and the smoke contains 50 of the cadmium. This, and the concentrations of radioactive elements, may indicate an additional health risk compared with commercial cigarettes. A study of three samples of marijuana indicates a similar level of risk from heavy metals

Blood lead levels in Jamaican school children.

Blood lead levels are reported for a total of 421 schoolchildren in 13 schools in rural and urban environments in Jamaica, including one highly contaminated community. In the rural areas blood lead levels ranged from 3 to 28.5 microg dl(-1), with a median of 9.2 microg dl(-1); the range and median in the urban schools were 4-34.7 and 16.6 microg dl(-1), respectively. Forty-two percent of the rural and 71% of the urban blood lead levels exceeded the US Centers for Disease Control and Prevention intervention level of 10 microg dl(-1). Except in the contaminated area, the relationship between soil lead levels, which in Jamaica are in general typical of tropical lateritic soils, and blood lead levels is not clear-cut. Very high blood lead levels of 18 to > 60 microg dl(-1) with a median of 35 microg dl(-1) were observed among children in the contaminated area, the site of a former lead ore processing plant. These high blood lead levels were significantly reduced, by the implementation of relatively simple mitigation strategies which involved isolation of the lead, education, and a food supplementation programme, to levels similar to those observed in the urban schools. These values, however, remain higher than are desirable and unfortunately, all the sources of lead are not yet identified. The recent discontinuation of the use of leaded petrol is expected to result in significant reductions in exposure to lead.

Undernutrition and elevated blood lead levels: effects on psychomotor development among Jamaican children.

OBJECTIVE: We examined whether or not the effect of elevated blood lead levels on children's psychomotor development was modified by their nutritional status. DESIGN: Anthropometry, developmental quotients (DQs), blood lead levels and haemoglobin were measured in lead exposed and unexposed children with different levels of nutritional status. Social background and maternal height and verbal intelligence were also measured. Testers, anthropometrists and interviewers established reliabilities with a trainer before the study began. SETTING: Children were from two suburban areas in Kingston, Jamaica. All measurements on the children were carried out at a research unit. Social background and maternal measurements were carried out at the children's homes. SUBJECTS: The exposed group comprised 58 children (3-6 years) attending the same preschool which was situated in a lead contaminated environment. The unexposed group comprised 53 children attending a nearby preschool without lead contamination. RESULTS: The exposed children had significantly higher blood lead levels and lower DQs, and their homes had poorer facilities than the unexposed children. The deficit in DQ was greater (10.6 points) among children with weight for height less than -1 SD (National Center for Health Statistics references) than among better nourished children (2 points). CONCLUSIONS: Undernourished children exposed to lead may have more serious developmental deficits than better nourished children.

The application of geographic information systems to geochemical studies in Jamaica.

The Centre for Nuclear Sciences (CNS) uses a raster based geographic information system (GIS), integrated with a relational database to store information on point sampled data, including concentrations of over 50 elements and/or ions in a variety of sample materials. These data are filtered in the GIS to create surface layers and are assigned colours according to percentile ranges allowing visual inspection to be used to identify significant features and trends. The database currently contains raster map layers for soils and geologic features, point site data for water and air, and vector data for roads, rivers and streams. While data are still being added to the database interesting results are already being obtained and a few instances where the GIS was used to assist in the data interpretation are reported.

Spatial pattern of arsenic and lead distributions in Jamaican soils.

The spatial patterns of arsenic and lead distribution in Jamaican soils were studied using the Geographical Resources Analysis Support System (GRASS) and data from an island wide soil survey. Arsenic and lead were analysed by instrumental neutron activation analysis (INAA) and energy-dispersive X-ray fluorescence (EDXRF) techniques. The frequency distribution of each element is discussed in relation to major lithological groups. The As-Pb background levels for different areas in Jamaica were estimated.

Heavy metals in Jamaican surface soils.

A regional survey of Jamaican surface soils has been conducted in which more than 200 samples were collected at a sample density of 1 per 64 km(2) across the island and analysed for total concentrations of 31 elements by instrumental neutron activation analysis (INAA), energy dispersive X-ray fluorescence (EDXRF) analysis and atomic absorption spectrophotometry (AAS). The aim of the survey was to begin the construction of a high-precision geochemical database to provide information on elemental levels in soils for application to environmental studies, agriculture, and human and animal health. Results on the regional scale are presented for As, Cd, Cu, Hg and Pb. Although Jamaican surface soils are enriched in several heavy metals compared with world soil means and crustal abundances, lead is of particular importance at this stage because of its occurrence in residential areas. Except for Cu, the distribution maps of these elements are highly correlated with bauxite which in Jamaica is associated with white limestone geology and residualterra rossa soils.

Lead in a residential environment in Jamaica.

The background levels of lead in Jamaica in soils and sediments, estimated at 37 mg kg(-1), are relatively high compared with world averages. Several areas have values in excess of this due to mineralisation and pollution. One such is the residential Hope Flats/Kintyre area in which levels of lead up to 2.5% are found in the soils and up to 8 µg kg(-1) in the water of the nearby Hope River. The blood lead levels of a sample of children were in the range 5.7-57 µg dl(-1). The high lead levels suggest a potential health risk, particularly for the children. This can be minimised by programmes which include community education, case management and abatement to reduce the lead exposure.