Safe levels of cadmium intake to prevent renal toxicity in human subjects

The present review attempts to provide an update of the scientific knowledge on the renal toxicity which occurs in human subjects as a result of chronic ingestion of low-level dietary Cd. It highlights important features of Cd toxicology and sources of uncertainty in the assessment of health risk due to dietary Cd. It also discusses potential mechanisms for increased susceptibility to Cd toxicity in individuals with diabetes. Exposure assessment on the basis of Cd levels in foodstuffs reveals that vegetables and cereals are the main sources of dietary Cd, although Cd is also found in meat, albeit to a lesser extent. Cd accumulates particularly in the kidney and liver, and hence offal contains relatively high amounts. Fish contains only small quantities of Cd, while crustaceans and molluscs may accumulate larger amounts from the aquatic environment. Data on Cd accumulation in human kidney and liver obtained from autopsy studies are presented, along with results of epidemiological studies showing the relationship between renal tubular dysfunction and kidney Cd burden. These findings suggest that a kidney Cd level of 50 mug/g wet weight is a maximum tolerable level in order to avoid abnormal kidney function. This renal Cd burden corresponds to a urinary Cd excretion of 2 mug/d. Accordingly, safe daily levels of Cd intake should be kept below 30 mug per person. Individual variations in Cd absorption and sensitivity to toxicity predicts that a dietary Cd intake of 30 mug/d may result in a slight renal dysfunction in about 1% of the adult population. The previous guideline for a maximum recommended Cd intake of 1 mug/kg body weight per d is thus shown to be too high to ensure that renal dysfunction does not occur as a result of dietary Cd intake

The epidemiology of hookworm, whipworm and pinworm in a south Indian fishing community

Imperial Users onl

The influence of individual, social group and household factors on the distribution of Ascaris lumbricoides within a community and implications for control strategies

The distribution of Ascaris lumbricoides within a community was examined at an initial mass anthelmintic treatment programme (January 1984) and following an 11-month period of reinfection (November 1984). Similar patterns of the negative binomial parameter k (an inverse measure of parasite aggregation) and the proportion of parasites within the most heavily infected quartile of the community were recorded at the two dates. The pattern of parasite aggregation within individuals, measured by parameter k, appears to be a stable characteristic of this host-parasite relationship. Significant variation in the intensity of infection was observed between households in the community. The number of family members living in the house strongly influenced the mean Ascaris burden and proportion of relatively heavy infections within adults and children. This finding suggests that the density of people in a house positively influences the frequency of exposure to infective stages of Ascaris, which in turn plays a major role in determining which individuals will harbour heavy infections. Positive correlations were recorded between the initial and reinfection burdens of individuals, relative to others in the community. The correlations were strongest in the youngest and oldest age groups and were more frequently significant among age-stratified groups of females, compared to males. A comparative examination of hypothetical treatment strategies suggests that for Ascaris infections in this community, targetting age groups with anthelmintic treatment would probably be more cost-effective in the long term in reducing the abundance of this parasite than selective treatment of individually identified heavy infections.</p

An investigation of hookworm infection and reinfection following mass anthelmintic treatment in the South Indian fishing community of Vairavankuppam

Hookworm infections, as assessed by counting worms expelled following anthelmintic treatment and by egg output, were found to be of low prevalence and intensity in a South Indian fishing community. The initial overall prevalence of infection in the community was 43 %, and the average burden was estimated at 2.2 hookworms per person. The age profiles of prevalence and intensity differed between males and females, with the latter harbouring significantly higher levels of infection. Children of both sexes under 10 years of age rarely harboured hookworms. Treatment with pyrantel pamoate was estimated to be 91 % effective in clearing hookworm infections. Egg counts made on stools collected during an 11-month period of reinfection indicated that female patients became reinfected soon after treatment, while little hookworm egg excretion was observed in males during the observation period following treatment. Females acquired a significantly higher number of worms during the reinfection period compared with males, although the average burden in females reached only 28% of the initial, pre-treatment level. The hookworm population consisted of predominantly Necator americanus, and less than 10% of Ancylostoma duodenale. The parasites were highly aggregated within the host population with 10% of the community harbouring over 65% of the total hookworms. Low values of the negative binomial aggregation parameter, k, (indicating extreme over-dispersion) were recorded in groups stratified by age and sex. Highly significant positive correlations were observed between the initial (pre-treatment) and reinfection worm burdens of female (but not of male) patients. It is suggested that occupational practices related to walking through areas contaminated with hookworm larvae play an important role in generating the observed patterns of infection within this community.</p

Epidemiology of Opisthorchis viverrini

Opisthorchis viverrini is a food borne trematode, important because of the sheer numbers of people infected and its serious morbidities such as hepatobiliary diseases and cholangiocarcinoma (CHCA). Although infections are identified throughout Southeast Asia, the epi-center is northeast Thailand, where high prevalence coexists with a high incidence of CHCA. In this review, we present the basic population features and the factors influencing transmission between the different hosts

The importance of host age and sex to patterns of reinfection with Ascaris lumbricoides following mass anthelmintic treatment in a South Indian fishing community

Analysis of egg and worm counts of Ascaris recorded at various intervals following a mass anthelmintic treatment programme in a South Indian fishing community is presented. Three indices of infection in the community are compared, namely the prevalence and intensity of egg output (at 2, 6 and 11 months following treatment) and the number of worms expelled following an 11 month period of reinfection. Detailed examination of these measurements revealed significant associations with patient sex and age. The age-prevalence profile of Ascaris infection changed little over time (except immediately following treatment) with the peak prevalence found in the 5–9 year age group. Although 85% of both males and females harboured Ascaris initially, the prevalence following 11 months reinfection was decreased, due to a significantly lower proportion of males being reinfected. By the 11th month of reinfection, the age-intensity profiles of egg output were similar to those observed at initial treatment in the older age groups (10 years and above) and in male children (< 10 years). However, a dramatic increase in the egg output of female children, greatly exceeding the initial mean, was observed within a 6 month period of reinfection. The intensity of egg output did not accurately reflect the abundance of Ascaris recovered via drug-induced expulsion following an 11 month period of reinfection. Although the egg output attained pre-intervention levels, the average worm intensity reached only half the initial value. The trends in the sex- and age-intensity profiles were consistent at the two sampling dates and showed similar patterns to the egg output curves. The relevance of the results to helminth control and the monitoring of reinfection is discussed.</p

To be or not to be: Recording Aboriginal Identity on Hospital Records

Accurate health information is a key component in the development of health improvement strategies. This paper provides a discussion of the challenges in improving hospital information systems in relation to indigenous patients. Based on interviews with both staff and patients of a major city hospital complex, a picture emerges of the need for bottom-up approaches to understanding perceptions of identity. Indigenous patients were found to be generally comfortable about identifying themselves on hospital records (if asked), but were often not clear why such questions were asked. On the other hand hospital staff were often uncomfortable about asking and were equally not always clear why such information was needed. Issues of accurate hospital record administration are discussed in relation to the attitudes and perceptions of both staff and patients

Promoting the health of Aboriginal Australians through empowerment: eliciting the components of the Family well-being empowerment and leadership programme

Most policies addressing Aboriginal health in Australia promote initiatives that are based on empowerment principles. Articulated programme components are necessary to support personal and group empowerment and to assist individuals in gaining the sense of control and purposefulness needed to exert their political and personal power in the face of the severe stress and powerlessness faced by the Australian Aboriginal people. This paper aims to provide a detailed description of the mechanisms underpinning a 'bottom-up' empowerment initiative, the Family well-being empowerment and leadership programme (FWB), and to analyze how the programme supports empowerment. The five stages of FWB were described and the validity of this model was assessed through the combination of participatory observation, documentation analysis, literature review, semi-structured interviews and iterative feedback with different analytical perspectives. Our study results articulated four distinct programme components: the setting plus inter-relational, educational and experiential actions. FWB is an example of the promotion of both outcome and process pathways towards empowerment. Potential applications of the programme are discussed

The healing journey: Empowering Aboriginal communities to close the health gap

Objectives: This paper presents two arguments relevant to both past and present efforts to improve Indigenous health. It advocates for ways of thinking about and doing health promotion that begin with empowerment to help people gain a greater level of control over their lives and circumstances. Conclusion: A combination of the strengths of different approaches is in fact an empowering, dialectical view that can be achieved by considering Aboriginal people not as children in need, but as capable and efficacious individuals