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Biomedical subjects

L London

Publications and source records attributed to L London.

At least 37 records · Page 2Linked to original sources
PubMed1999

The 'dop' system, alcohol abuse and social control amongst farm workers in South Africa: a public health challenge.

Many farm workers in South Africa continue to live and work under adverse conditions that are the legacy of apartheid policies. Despite its official prohibition, the arrangement by which workers are given alcohol' as a benefit of employment, known as the 'dop' system, appears to persist. Even though it is a minority of farms that currently actively practice the dop system, the ramifications of the historical 'institutionalisation of massive alcohol consumption are widespread. Heavy alcohol consumption is not only directly injurious to the health of farm workers and their families, but places them at risk to various social and environmental hazards. This is illustrated in a case of pesticide poisoning in which 24 workers were poisoned when given wine contaminated with the carbamate insecticide aldicarb. The case illustrates (i) the ongoing application of the dop system on farms in South Africa and (ii) the interaction between social factors and chemical exposures amongst farm workers. Public perceptions about the natural tendencies of 'coloured' people to drink heavily have much to do with perpetuating the dop system, and reinforcing a system geared towards the social control of rural farm workers and their families. The dop system poses a major challenge to the public health authorities in South Africa who are charged with the task of restructuring health services to address the human rights and health needs of marginal farming communities within a primary health care framework.

Agriculture↗
PubMed1999

Correlation of medial/lateral rotation of the humerus with glenohumeral translation.

OBJECTIVES: To correlate glenohumeral translation in the anterior/posterior direction with medial and lateral rotation of the humerus. In addition, the length of the anterior and posterior component of the glenohumeral capsuloligamentous complex was varied in order to gain insight into the contribution of each component to limiting translation. All measurements were made with the humerus positioned at 90 degrees of abduction and 0 degrees of flexion/ extension. METHODS: Six fresh cadaveric shoulders were used. Each scapula was mounted in a cement pot to rest it in its correct anatomical position. Seven tests were carried out on each shoulder. A series of measurements of translation of the humerus in the anterior direction and posterior direction were taken at 20 degrees intervals of lateral rotation and then at 20 degrees intervals of medial rotation until the limit of lateral or medial rotation had clearly been reached (test 1). The capsuloligamentous complex was then incised and a beaded chain and catches were sutured across the joint to mimic the capsuloligamentous complex at different lengths (tests 2 to 7). RESULTS/CONCLUSIONS: (a) When the glenohumeral capsuloligamentous complex is intact, the humerus translates maximally in the glenoid (between 20 and 30 mm) when the humerus is between 40 degrees and 100 degrees of lateral rotation. (b) As the glenohumeral capsuloligamentous complex increases in length, so does the extent of translation. (c) In medial rotation, the length of the posterior capsule, rather than the length of the anterior capsule, has the greater effect on anterior/posterior translation. (d) In lateral rotation the length of the anterior capsule, rather than the length of the posterior capsule, has the greater effect on anterior/posterior translation. (e) The glenohumeral ligamentous complex acts more as a cuff, enclosing the joint, rather than as a sling, as is commonly thought.

Aged↗
PubMed1999

Long-term respiratory health effects of the herbicide, paraquat, among workers in the Western Cape.

OBJECTIVE: To evaluate the possible effects of paraquat spraying among workers on deciduous fruit farms in the Western Cape, South Africa. Paraquat is a commonly used herbicide world wide and is a well documented cause of pulmonary fibrosis in studies of laboratory animals and in humans after exposure to a high dose (usually accidental or as parasuicide). The respiratory effects of long term, low dose exposure to paraquat have not been fully evaluated. METHODS: A cross sectional study of 126 workers. Administered questionnaires generated information on exposure, respiratory symptoms, and potential confounding variables. Spirometry and gas transfer were measured and chest radiographs performed. Oxygen desaturation on exercise testing was by oximetry during a modified stage one exercise test. RESULTS: No association was found between long term exposure to paraquat and reported symptoms, spirometry (forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), FEV1/FVC) and gas transfer (TLCO and KCO) or chest radiography. Multivariate analysis showed a significant relation between measures of long term exposure to paraquat and arterial oxygen desaturation during exercise independent of short term exposure. CONCLUSION: Previous studies have not shown a significant relation between measures of exposure to paraquat and standard tests of lung function. Arterial oxygen desaturation during exercise represents a more sensitive test. The findings indicate that working with paraquat under usual field conditions is associated with abnormal exercise physiology in a dose dependent fashion independent of recent exposure and acute poisoning events.

Adult↗
PubMed1998

An ecological model for school-based mental health services for urban low-income aggressive children.

An ecological model for school-based mental health services that targets urban low-income aggressive children--a highly vulnerable and underserved population--is presented. The goals of the model are to increase children's and teachers' involvement in the delivery of services and to increase the integration of these services into existing school resources and activities. The model proposes that mental health service providers work in collaboration with teachers to deliver services that (1) can be managed by existing school resources and personnel, (2) are related to empirically based factors associated with reduced aggression and increased social functioning, and (3) are group administered to increase the number of children served and to reduce stigmatization associated with mental health services. The model is individualized and flexible by acknowledging that contexts for aggression differ across classrooms and children and by providing services specific to those contexts. Two studies are presented illustrating the application of this model to decrease aggression and increase academic engagement in low-income urban public schools.

Achievement↗
PubMed1998

Teaching medical students on the ethical dimensions of human rights: meeting the challenge in South Africa.

SETTING: Previous health policies in South Africa neglected the teaching of ethics and human rights to health professionals. In April 1995, a pilot course was run at the University of Cape Town in which the ethical dimensions of human rights issues in South Africa were explored. OBJECTIVES: To compare knowledge and attitudes of participating students with a group of control students. DESIGN: Retrospective cohort study. SUBJECTS: Seventeen fourth-year medical students who participated in the course and 13 control students from the same class, matched for gender. INTERVENTIONS: Students participated in a one-week module on ethics and human rights. Five months after the course had been run, students completed a semi-structured questionnaire exploring their knowledge and attitudes with regards to ethics and human rights issues. MAIN OUTCOME MEASURES: Knowledge scores, attitude scores and various individual indicators of attitude. RESULTS: Clear benefits for overall knowledge score, for four out of five individual knowledge questions and for one of the attitude questions, were demonstrated. Participating students also appeared to be more convinced of the need for teaching on the ethical dimensions of human rights at postgraduate level and that such teaching should also be integrated in the curriculum. The low response rate amongst controls may have selected students who were more socially conscious, thereby leading to an underestimate of the true impact of the course. CONCLUSION: The evaluation indicates clear benefits of the course for undergraduate students, and supports arguments for the inclusion of such courses in the training of health professionals. This is particularly important given the challenges posed by the Truth and Reconciliation Commission to the health professions to address past complicity in human rights abuses through reorientation of medical training in South Africa.

Adult↗
PubMed1998

Use of a crop and job specific exposure matrix for retrospective assessment of long-term exposure in studies of chronic neurotoxic effects of agrichemicals.

RATIONALE: Job exposure matrices (JEMs) are widely used in occupational epidemiology, particularly when biological or environmental monitoring data are scanty. However, as with most exposure estimates, JEMs may be vulnerable to misclassification. OBJECTIVES: To estimate the long term exposure of farm workers based on a JEM developed for use in a study of the neurotoxic effects of organophosphates and to evaluate the repeatability and validity of the JEM. METHODS: A JEM was constructed with secondary data from industry and expert opinion of the estimate of agrichemical exposure within every possible job activity in the JEM to weight job days for exposure to organophosphates. Cumulative lifetime and average intensity exposure of organophosphate exposure were calculated for 163 pesticide applicators and 84 controls. Repeat questionnaires were given to 29 participants three months later to test repeatability of measurements. The ability of JEM based exposure to predict a known marker of organophosphate exposure was used to validate the JEM. RESULTS: Cumulative lifetime exposure as measured in kg organophosphate exposure, was significantly associated with erythrocyte cholinesterase concentrations (partial r2 = 5%; p < 0.01), controlled for a range of confounders. Repeatability in a subsample of 29 workers of the estimates of cumulative (Pearson's r = 0.67; 95% confidence interval (95% CI) 0.41 to 0.83), and average lifetime intensity of exposure (Pearson's r = 0.60 95% CI 0.31 to 0.79) was adequate. CONCLUSION: The JEM seems promising for farming settings, particularly in developing countries where data on chemical application and biological monitoring are unavailable.

Agriculture↗
PubMed1998

AIDS control and the workplace: the role of occupational health services in South Africa.

AIDS interventions typically fail to address the disjuncture between private behaviors and the social determinants of HIV infection. Data from a telephone survey of manufacturing companies and a postal survey of occupational health nurses in the Western Cape, South Africa, were used to explore the possible role of occupational health services in prevention and control of AIDS. The author found limited evidence of worker involvement in AIDS programs, particularly in companies with occupational health professionals. The management of sexually transmitted diseases was incomplete. Mandatory pre-employment testing of workers for HIV was not widespread. Respondents' opinions on priorities for AIDS prevention and control reflected a preoccupation with knowledge transfer. To ensure their effectiveness, workplace AIDS programs must improve worker participation and integrate AIDS prevention in general workplace health and safety programs. In addition, education programs must develop objectives within a critical theoretical understanding of the behavioral issues relevant to AIDS prevention, and must emphasize the empowerment of women in the workplace. In the context of the present restructuring of health services in South Africa, occupational health services, using the strategies outlined, can make a major contribution to national AIDS prevention and control.

Acquired Immunodeficiency Syndrome↗
PubMed1998

Effects of long-term organophosphate exposures on neurological symptoms, vibration sense and tremor among South African farm workers.

OBJECTIVES: This study assessed the relationship between long-term exposure to organophosphate insecticides and neurological symptoms, vibration sense, and motor tremor after control for the effect of past poisoning and acute exposure. METHODS: This cross-sectional study included 164 pesticide applicators and 83 nonspraying reference workers on deciduous fruit farms. The workers were tested on the Vibratron II, on tests of dynamic and static tremor, and for a set of neurological and "dummy" symptoms. Exposure was derived with the use of a job-exposure matrix for pesticides in agriculture. RESULTS: Compared with nonapplicators, current applicators reported significantly more dizziness, sleepiness, and headache and had a higher overall neurological symptom score. This association remained statistically significant after multiple logistic regression analyses controlling for a range of confounders and effect modifiers [odds ratio (OR) 2.25, for current applicators having high neurological score, 95% confidence interval (95% CI) 1.15-4.39]. The average lifetime intensity of organophosphate exposure was nonsignificantly associated with both neurological (OR 1.98, 95% CI 0.49-7.94) and "dummy" symptoms (OR 2.37, 95% CI 0.54-10.35). Previous pesticide poisoning was significantly associated with the neurological scores (OR 4.08, 95% CI 1.48-11.22) but not with the "dummy" symptoms. Vibration sense outcomes were associated with age and height, but not with the organophosphate exposure measures. In the multiple linear regression modeling for tremor intensity in the dominant hand, recent organophosphate exposure in the past 10 days was a significant predictor (partial correlation coefficient = 0.04), but none of the long-term organophosphate exposure measures were significant. CONCLUSIONS: Strong evidence was found for an association between symptom outcomes and past organophosphate poisoning and between symptom outcomes and current spray activity. In contrast to symptoms, there was no association between either past poisoning or current spray activity and vibration sense or tremor outcome. Long-term organophosphate exposure did not appear to predict symptoms, vibration sense, or tremor outcome.

Adult↗
PubMed1998

The UDHR and The Limits of Medical Ethics: The Case of South Africa.

The leadership of South Africa's medical profession remained silent in the face of gross human rights violations by the apartheid government or affirmatively defended the government's conduct. While there were strong cultural and economic reasons for this alliance between leaders of the medical profession and the apartheid state, the leadership also embraced western medical ethics. As a result, when confronted about its conduct, it continually sought to defend its behavior on traditional ethical grounds. This article looks at the nature of that "ethical defense" in three areas, torture in detention, racial discrimination in health services, and breach of confidentiality in the case of political activists. The article concludes that the rules of medical ethics left too great a space for making such a defense and urges that ethical rules consistent with the Universal Declaration of Human Rights be adopted.

Journal Article↗
PubMed1998

Health status among farm workers in the Western Cape--collateral evidence from a study of occupational hazards.

MOTIVATION: Farm workers are a marginalised occupational group whose poor living and working conditions may place them at increased risk for occupational and non-occupational morbidity and mortality. Research into the health status of farm workers has been neglected in the past. AIMS AND OBJECTIVES: As part of an investigation into the neurological and neurobehavioural effects of exposure to organophosphate insecticides, this study describes the demographics, life histories, risk factors for chronic illness and selected indicators of general health status among a group of farm workers in the Western Cape. STUDY DESIGN: Cross-sectional study conducted in the deciduous fruit farming industry in 1993. SUBJECTS: 164 pesticide applicators and 83 non-spraying controls (all men) from 73 farms, frequency matched for age and education. MEASUREMENTS: A structured questionnaire, venous blood sample for serum and erythrocyte cholinesterase, albumin, gamma glutamyl transferase and haemoglobin assessment, height and weight measurement. RESULTS: Most farm workers were children of farm workers and had lived and worked on farms for most of their lives. The study found substantial levels of illiteracy (21-44%, depending on the definition) and innumeracy (4%) and evidence of a significant morbidity burden: high levels of alcohol intake and ongoing reported application of the 'dop' system, high levels of head injury (70% of subjects) and evidence of substantial adult undernutrition. Protective equipment was relatively well distributed and used, although certain work activities (such as acting as a human marker) continue to pose substantial exposure hazards. There were no differences in respect of cholinesterase levels between spray applicators and controls, although past poisoning was reported by 9% of subjects. CONCLUSION: Farm workers appear to be a closed community with a high disease burden. Their health needs pose substantial challenges to the public health authorities.

Adult↗
PubMed1998

The 'dop' system around Stellenbosch--results of a farm survey.

OBJECTIVES: To document the number of farms operating a 'dop' system (payment of workers with alcohol instead of wages), to estimate the number of farm workers affected, to describe how the system operated and to characterise adverse social conditions on the farms. POPULATION: Farms served by the mobile clinics of the Cape Metropolitan Council's Health Department in the Stellenbosch area. METHODS: Cross-sectional prevalence survey. Nurses collected data from patients attending mobile clinics. RESULTS: A prevalence of 9.5% was detected in respect of farms operating the dop system, with an estimated 780 workers affected. The most common practice was a daily provision of 750 ml wine to male workers. Social conditions on the farms in question were poor and wages were low. Child malnutrition was the most common health problem identified. CONCLUSION: The dop system, although illegal, has been documented to occur in the Stellenbosch area. Programmes to address the dop system and alcohol abuse, based on a primary health care approach, are a priority in the rural areas of the Western Cape.

Agricultural Workers' Diseases↗
PubMed1998

Enhanced surveillance for pesticide poisoning in the Western Cape--an elusive target.

AIM: The poor state of reporting of pesticide poisoning is widely recognised as a hindrance to the development of preventive programmes that aim to address this important cause of mortality and morbidity in farm workers. This study aimed to assess the extent to which notification could be improved by enhancing passive surveillance procedures. METHODS: An awareness campaign targeting a range of health care providers was conducted in a rural farming area. This included improving the availability of cholinesterase testing and encouraging all providers to notify on suspicion. Existing reporting forms were supplemented with additional questions, and notification took place through existing channels. The rate of notification in the study area was compared with that in surrounding areas and previous years. RESULTS: Fourteen poisoning events involving 56 people were reported, with 2 events together accounting for 44 cases. All patients were hospitalised. Over 90% of cases occurred on farms, with the farm store being the most common source of pesticide. Only one case was notified by a general practitioner. The rate of notification in the study area was approximately tenfold that of previous years and of the surrounding area for the same year (P < 0.0001). CONCLUSION: Although the enhanced surveillance programme resulted in an increase in notifications, the programme appears to have been ineffective in detecting mild cases of poisoning or in improving notification on suspicion by general practitioners.

Adolescent↗
PubMed1997

An investigation into neurologic and neurobehavioral effects of long-term agrichemical use among deciduous fruit farm workers in the Western Cape, South Africa.

Long-term exposure to organophosphates (OPs) in the absence of acute poisoning is increasingly suspected of causing chronic neurologic and neurobehavioral effects. A cross-sectional survey of 163 spray operators on deciduous fruit farms in the Western Cape, South Africa, and 84 nonspraying labororers was conducted in 1993 to investigate the relationship between long-term OP exposures and neurological and neurobehavioral outcomes. The study also sought to evaluate the performance of a set of neurobehavioral test batteries based on the information-processing theory of cognitive psychology, relative to the more established World Health Organization's Neurobehavioral Core Test Battery (WHO NCTB). These information-processing tests were designed for use in studies of subjects with little education, which are frequently conducted in developing countries in agriculture. They draw on experience from a previous South African study in which problems were encountered with a lack of cross-cultural validity of conventional test batteries. No evidence was found of a relationship between long-term OP exposure and loss of vibration sense. Small associations were found with the NCTB Pursuit-Aiming and Santa Ana (nondominant hand) subtests. The overall evidence of neurologic and neurobehavioral effects of long-term OP exposure was small; exposure misclassification may have contributed to this finding. Important confounders such as brain injury, alcohol consumption, and nutritional status were identified.

Agricultural Workers' Diseases↗