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Biomedical subjects

A A Lovett

Publications and source records attributed to A A Lovett.

11 recordsLinked to original sources
PubMed1998

The public health risks of Lyme disease in Breckland, U.K.: an investigation of environmental and social factors.

This paper considers the public health risks of Lyme disease, a borrelial infection transmitted to humans chiefly by nymphal Ixodes ticks. A study undertaken in the Breckland area of East Anglia, U.K., combined analysis of the spatial and temporal factors affecting tick activity at recreational sites with a survey of current levels of disease awareness among visitors to these locations. Significant relationships were found between densities of questing ticks and vegetation type, relative humidity and temperature. More than two thirds of the general public visiting the sites were aware ticks could carry diseases, but only 13% recognized an unfed nymph, and under half knew that Lyme disease could be contracted from tick bites. Such results need to be taken into account when formulating public health and education measures.

Borrelia burgdorferi Group↗
PubMed1997

Validation of a congener specific method for ortho and non-ortho substituted polychlorinated biphenyls in fruit and vegetable samples.

An on-line procedure has been developed and validated for the clean-up and fractionation of ortho and non-ortho-PCBs in fruit and vegetable samples. The procedure combines silica/acid and carbon/glass fibre columns with gas chromatography-mass spectrometry. Chromatography on carbon/glass fibre allowed collection of mono-ortho/di-ortho and non-ortho-PCB fractions, which were determined separately by GC-MS. The method was validated by replicate analyses and by inter-laboratory comparison of data for PCB congeners determined in fruit and vegetable samples collected in South Wales. The concurrent determination of ortho and non-ortho substituted PCBs is reported with recoveries ranging from 55-95% and a mean intra-laboratory precision (%COV) of 9.5% for apple extracts.

Chromatography↗
PubMed1997

Using GIS in risk analysis: a case study of hazardous waste transport.

This paper provides an illustration of how a geographic information system (GIS) can be used in risk analysis. It focuses on liquid hazardous waste transport and utilizes records archived by the London Waste Regulatory Authority. This data source provides information on the origin and destination of each waste stream, but not the route followed during transport. A GIS was therefore employed to predict the paths used, taking into account different routing criteria and characteristics of the available road network. Details were also assembled on population distribution and ground-water vulnerability, thus providing a basis for evaluating the potential consequences of a waste spillage during transport. Four routing scenarios were implemented to identify sections of road which consistently saw heavy traffic. These simulations also highlighted that some interventions could lead to risk tradeoffs rather than hazard mitigation. Many parts of the research would not have been possible without a GIS, and the study demonstrates the considerable potential of such software in environmental risk assessment and management.

England↗
PubMed1995

Evaluation of methods for calculating census health indicators for GP practices.

The patients registered with a general practice are usually spread over many census areas and overlap with the distribution of neighbouring practices, so a validated method of aggregating census data to describe the characteristics of practice patients is required. Four methods were used to provide estimates of the percentage of patients aged 75 years and over from census data for 81 practices in Suffolk, England, and these were compared with values derived from the FHSA patient register. Census values for practice areas produced better estimates than those based on the location of the surgery, but the best methods were based on patient-weighted averages of ward and enumeration district data. The finer geographical detail of enumeration districts did not produce substantially more accurate estimates than the ward-level data: both gave estimates with limits of agreement within 2% of the patient register values. Errors in the census, errors in patient registers and selective geographical distributions of practice patients prevent close matching of census and register measures, but two of the methods tested produced estimates that allow broad comparisons between practices.

Aged↗
PubMed1995

Comparison of ward population estimates from FHSA patient registers with the 1991 Census.

"Postcode addresses from National Health Service patient registers for Norfolk and Suffolk [counties in England] current on census day 1991 were assigned to census wards, and estimates of populations in wards were produced for the total population and for twelve age-sex groups. These were compared with adjusted counts of usual residents from the 1991 Census." The results indicate that family health service authority registers "are an acceptable alternative to the census for population estimation purposes. This supports recent arguments for wider use of population registers and suggests that they may be particularly valuable as a source of intercensal information."

Age Distribution↗
PubMed1990

Congenital malformations in the Fylde region of Lancashire, England 1957-1973.

This paper uses data collected by a consultant paediatrician to examine variations in the prevalence of neural tube and cardiovascular malformations within the Fylde region of North West England. Results at the district scale indicate contrasts in the geographical distributions of the two classes of malformation and these are then further assessed via a case-control study which standardises for factors such as date of conception, age of mother and parity. The results of this study suggest that there were wards in Blackpool and Fleetwood with unusually high prevalences of neural tube defects. Further research is being undertaken to identify the causes of these concentrations.

Case-Control Studies↗
PubMed1986

Analysing geographic variations in mortality using Poisson regression: the example of ischaemic heart disease in England and Wales 1969-1973.

This paper describes how Poisson regression techniques can be used to examine the relationship between mortality and possible explanatory variables over a series of areas in cases where the number of deaths involved is relatively low. As an example an analysis is carried out on deaths from ischaemic heart disease among young adults in the county boroughs of England and Wales during 1969-1973. The results of the study indicate that the number of deaths was higher for males than females and was positively related to age, the size of the 'at risk' population and crowding, but negatively associated with water hardness and the size of the New Commonwealth population. A comparison of the Poisson and log-normal regression models clearly shows that the latter provides an inferior goodness of fit and unreliable results. It is therefore concluded that when the number of deaths is small there are both theoretical and practical advantages in using Poisson regression to analyse mortality data.

Adolescent↗
PubMedDate not supplied

PCB and PCDD/DF congeners in locally grown fruit and vegetable samples in Wales and England.

A survey was undertaken of PCB and PCDD/DF congeners in fruit and vegetables grown in an urban areas close to a chemical waste incinerator and three rural locations. All of the concentrations detected were low and there was considerable overlap between those found in urban and rural samples. Some similarities with the congener composition of air samples were identified and concentrations in apple skin were noticeably higher than those in the flesh of the fruit. These results suggest that atmospheric deposition was an important contamination pathway. Assessments using the highest concentrations found indicated that consumption of such fruit and vegetables would represent an additional 3% of the normal dietary intake for PCBs and 8% for PCDD/DFs.

Benzofurans↗
PubMedDate not supplied

PCB and PCDD/DF concentrations in egg and poultry meat samples from known urban and rural locations in Wales and England.

A survey was undertaken of PCB and PCDD/DF congeners in eggs and poultry meat from a smallholding close to a chemical waste incinerator, other sites in the surrounding district, and three rural locations. The concentrations from the site close to the incinerator were appreciably greater than those found elsewhere, although the contrast was less marked for poultry meat than eggs. All types of poultry produce displayed noticeable variations in congener composition when the samples were grouped according to geographical origin. These results support the view that the environment in which poultry live does influence the PCB and PCDD/DF characteristics of their products. Exposure calculations indicated that consumption of eggs from the site close to the incinerator would constitute a substantial proportion of recommended daily intakes for such contaminants and at the present time these products are not being eaten.

Animals↗