Does organic farming reduce environmental impacts?--a meta-analysis of European research.

Organic farming practices have been promoted as, inter alia, reducing the environmental impacts of agriculture. This meta-analysis systematically analyses published studies that compare environmental impacts of organic and conventional farming in Europe. The results show that organic farming practices generally have positive impacts on the environment per unit of area, but not necessarily per product unit. Organic farms tend to have higher soil organic matter content and lower nutrient losses (nitrogen leaching, nitrous oxide emissions and ammonia emissions) per unit of field area. However, ammonia emissions, nitrogen leaching and nitrous oxide emissions per product unit were higher from organic systems. Organic systems had lower energy requirements, but higher land use, eutrophication potential and acidification potential per product unit. The variation within the results across different studies was wide due to differences in the systems compared and research methods used. The only impacts that were found to differ significantly between the systems were soil organic matter content, nitrogen leaching, nitrous oxide emissions per unit of field area, energy use and land use. Most of the studies that compared biodiversity in organic and conventional farming demonstrated lower environmental impacts from organic farming. The key challenges in conventional farming are to improve soil quality (by versatile crop rotations and additions of organic material), recycle nutrients and enhance and protect biodiversity. In organic farming, the main challenges are to improve the nutrient management and increase yields. In order to reduce the environmental impacts of farming in Europe, research efforts and policies should be targeted to developing farming systems that produce high yields with low negative environmental impacts drawing on techniques from both organic and conventional systems.

Caries prevalence and fluoride use in low SES children in Clermont-Ferrand (France).

OBJECTIVE: To evaluate the association between dental caries experience and preventive behaviours of children residing in a deprived area in Clermont-Ferrand (France). PARTICIPANTS AND METHODS: All 4-5 yr-olds attending nine schools in deprived areas of the city were invited to participate and 81% (n=282) consented and were examined. Dental caries was recorded at the dentine threshold. Parents completed a questionnaire concerning family demographics and the child's use of fluoride. Non-parametric tests and logistic regression assessed the relative importance of SES and fluoride variables on dental status (dt>1). RESULTS: Fifty four (19%) of the examined children were living in families with an immigrant background, 33% were fully covered by the national health insurance programme for deprived families. Caries experience was high; mean dft was 1.94 (3.31) and 30% of the children had >1 carious teeth. Thirty percent of the families reported using fluoridated salt. Tooth brushing once daily was reported for 39% and twice daily for 26%. Parents declared supervising tooth brushing for 60%. Two thirds of the children, according to their parents, used fluoride supplement between birth and two years. Supervised tooth brushing was significantly correlated with lower mean dt scores. Systemic fluoride use was poorly related to dental caries Immigrant background, family size, type of health insurance and mother's unemployment were significantly correlated with caries prevalence. In multivariate analysis, immigrant status, supervised tooth brushing and parental knowledge about fluoride in toothpastes were significant caries predictors. CONCLUSIONS: The majority of low SES children did not practice effective caries prevention; few reported twice daily brushing with fluoride toothpaste. Caries experience was very high and much was untreated. Immigrant status, supervised tooth brushing and parental knowledge about fluoride in toothpastes were significant caries predictors.

Adaptation of the animal welfare assessment grid (AWAG) for monitoring animal welfare in zoological collections.

Animal welfare monitoring is an essential part of zoo management and a legal requirement in many countries. Historically, a variety of welfare audits have been proposed to assist zoo managers. Unfortunately, there are a number of issues with these assessments, including lack of species information, validated tests and the overall complexity of these audits which make them difficult to implement in practice. The animal welfare assessment grid (AWAG) has previously been proposed as an animal welfare monitoring tool for animals used in research programmes. This computer-based system was successfully adapted for use in a zoo setting with two taxonomic groups: primates and birds. This tool is simple to use and provides continuous monitoring based on cumulative lifetime assessment. It is suggested as an alternative, practical method for welfare monitoring in zoos.

Tooth follicle extirpation and uvulectomy.

Migration is not only the movement of people, but also of their culture, customs and beliefs. As more people from developing countries in Africa migrate to industrialized countries, the more likely health professionals will find themselves providing care for people of whose customs and practices they have little knowledge. This review of the literature suggests that removal of deciduous canine follicles and uvulectomy are frequently practised in some African and neighbouring countries. Reasons given for deciduous canine extirpation include the prevention of vomiting, fever and diarrhoea. The indications for uvulectomy appear widespread, including treatment for persistent fever, coughing and growth retardation. The practices are usually performed by traditional healers. Risks for children who undergo these procedures are extensive, including septicaemia, potential for HIV transmission, numerous dental complications and death. With improved understanding between Western health teams and local, traditional people, an improved system may develop whereby the two systems can work together in providing improved health outcomes for the people.

Delays in treatment in the cancer services: impact on cancer stage and survival.

This study describes waiting times for cancer treatment in Ireland, tests for differences between health board areas and investigates if delay affected cancer stage or prognosis. We measured the times between referral, outpatient attendance and treatment for all patients diagnosed with five common cancers in Ireland in 1999. There was a four-fold spread of waiting time between the 25th and 75th centile. The time from referral to treatment was shortest for breast cancer (median 4 weeks), twice this for colorectal cancer, lung cancer and lymphoma, and 15 weeks for prostate cancer. Delays varied significantly, but not consistently, between health boards. Patients with longer waiting times generally had less advanced disease and better survival, suggesting that typical delays are not of clinical significance, but that patients with advanced disease are probably being "fast-tracked" by GPs and hospitals.

Relation between blood pressure and stroke mortality.

The relation between stroke mortality and blood pressure was investigated in 10,186 hypertensive patients followed up in the Department of Health Hypertension Care Computing Project for an average of 9 years. An untreated blood pressure measurement was available in 3,472 men and 3,405 women. The age-adjusted risk of stroke death increased by 1% for every 1 mm Hg increase in untreated systolic blood pressure. The relative hazard rate was 1.014 (95% confidence interval [CI], 1.007, 1.021) in men and 1.009 (1.003, 1.016) in women. The corresponding increases for 1 mm Hg for untreated diastolic blood pressure were almost 3% in men and again 1% in women (relative hazard rate 1.026 [95% CI, 1.014, 1.038] in men and 1.010 [1.000, 1.021] in women). Treated blood pressure measurements were available in 3,073 men and 3,148 women. Stroke mortality increased by 2% for a 1 mm Hg increase in treated systolic pressure and 3% for the corresponding increase in diastolic blood pressure. The relation between stroke mortality and blood pressure was similar over and under the age of 65, although the increase in mortality with pressure was greater for treated diastolic blood pressure in women under the age of 65 than over this age. There was no evidence for a J-shaped relation between stroke mortality and either systolic or diastolic pressure in men. In women there was a suggestion of such a relation, but since this relation was also observed for untreated pressures, any increase in risk at lower pressures is unlikely to be a result of treatment.

Treated blood pressure, rather than pretreatment, predicts survival in hypertensive patients. A report from the DHSS Hypertension Care Computing Project (DHCCP).

A group of hypertensive patients (n = 2855) with an untreated diastolic blood pressure greater than or equal to 90 mmHg were followed in the Department of Health and Social Security (DHSS) Hypertension Care Computing Project (DHCCP) for periods of up to 10 years. During this period 191 of these patients died. Survival was assessed in relation to pretreatment blood pressure levels and blood pressure achieved during treatment. The blood pressure during treatment was a useful predictor of mortality, but the pretreatment pressure was not. After adjusting for age, mortality was particularly related to the height of the systolic and diastolic blood pressure during the second and third years of treatment. In men, age-standardized 5-year mortality was greater than 10% in those with a first year treated systolic pressure greater than 150 mmHg or a diastolic pressure greater than 95 mmHg. In women, age standardized 5-year mortality was greater than 5% with the same levels of treated blood pressure. The longest survival occurred with the lowest bands of treated pressure, i.e. systolic pressure less than 140 and diastolic pressure less than 90 mmHg; the 5-year mortality being less than 7% in men and less than 3% in women. Treated systolic and diastolic pressures were useful in predicting death from ischaemic heart disease (IHD).

Mortality associated with captopril and enalapril: a report from the DHSS Hypertension Care Computing Project.

In 1986, the Committee on Safety of Medicines published a report suggesting that enalapril may have an adverse effect on renal function. The prescription event monitoring scheme subsequently published figures on adverse drug reactions and mortality for patients treated with enalapril. They concluded that enalapril did not have an adverse effect on renal function and survival. Similar data were not available for captopril, as the drug was marketed before prescription event monitoring had been developed. In the Department of Health and Social Security (DHSS) Hypertension Care Computing Project (DHCCP), 368 hypertensive patients treated with captopril and 371 treated with enalapril were followed for an average of 3.1 and 1.6 years, respectively. Thirty-two patients died; none had renal failure as an underlying cause of death. The death rate was similar in both drug groups, at 17.5 (enalapril) and 24.0 (captopril) per 1000 patient-years. The present report shows that, for patients treated for high blood pressure, the relative risk of mortality with captopril compared with enalapril was 1.37, an insignificant difference (95% confidence interval 0.63, 2.98).

The survival of treated hypertensive patients and their causes of death: a report from the DHSS hypertensive care computing project (DHCCP).

A prospective study has been carried out to determine the causes of death and risk factors for survival in 4994 patients referred with a diagnosis of hypertension to hospital specialist clinics and 457 patients treated by their general practitioners for this condition. At the time of entering the prospective study, 69% of the patients were already being treated for hypertension. Four hundred and eleven patients have died, and their causes of death and death rates have been compared with the rates for the population of England and Wales. Ischaemic heart disease accounted for over one-third of the deaths and stroke for one-fifth. The death rates for these conditions were two to five times those expected for men and women aged 50-59 years and up to twice the rate expected for the age group 60-69 years. Survival in these selected patients was impaired by the following independent risk indicators: cigarette smoking, previous history of myocardial infarction or stroke, diagnosis of angina, impaired renal function and raised blood sugar. The following factors were not independent positive risk factors: smoking a pipe or cigars, obesity, a low plasma potassium and an elevated serum uric acid.

Relation between treated blood pressure and death from ischaemic heart disease at different ages: a report from the Department of Health Hypertension Care Computing Project.

OBJECTIVE: To determine the relation between mortality from ischaemic heart disease (IHD) and treated blood pressure at different ages. DESIGN: Prospectively, 6216 patients were studied for a mean of 107 months. SETTING: Of the total patients, 95% were followed in five hospital-based hypertension clinics and the remainder in four group general practices. PATIENTS: Respectively, 2250 and 2126 hypertensive men and women aged < 60 years and 822 and 1018 aged > or = 60 years. MAIN OUTCOME MEASURES: Mortality (any mention on the death certificate) from IHD. RESULTS: Four hundred and sixty-seven patients died with IHD mentioned on the death certificate. The relation between both diastolic blood pressure (DBP) and systolic blood pressure (SBP) during the first 3-12 months of treatment and subsequent IHD mortality was examined. Under the age of 60 years the relative hazard rate (RHR) for death from IHD tended to increase with DBP in both men and women. Above the age of 60 years there was no important or significant relation between IHD mortality and treated DBP. For SBP there was no reduction in the positive relation between IHD mortality and blood pressure in the older age groups. The RHR for SBP ranged between 1.008 and 1.021 in men and women over and under the age of 60 years. CONCLUSIONS: The positive relation between DBP and IHD mortality decreased with increasing age and, in women aged > or = 60 years, even inverted, partly explaining the negative relation reported between DBP and total mortality in the very old.

Dental caries and fluoride exposure in Western Australia.

Most water supplies in Western Australia (WA) have been fluoridated since about 1968, but one region has persistently resisted. Supplement use has been encouraged there, and fluoride toothpaste is widely used. Caries prevalence and caries experience in children in Perth (F- 0.8 mg/L) have declined steadily since fluoridation, but in the Bunbury region (F- less than 0.2 mg/L), caries measures remain higher than in Perth. The purpose of this study was to correlate the magnitude and timing of fluoride exposure with caries experience. Altogether, 592 randomly selected children born in 1978 (mean age, 11.8 years) in Perth and the Bunbury region provided residence and fluoride exposure information for the periods from birth to four and from four to 12 years of age. Caries experience was recorded clinically in accordance with DMFT and WHO criteria. Sixty-one percent had been continuous residents of fluoridated areas from birth to four years, and 51% between the ages of four and 12 years. Fluoride supplement use was low. By the age of 1.5 years, 42% had used toothpaste. The prevalence of caries was 0.38 in Perth and 0.61 in the Bunbury region, and mean DMFT scores were 0.89 (SD, 1.39) and 1.57 (SD, 1.60), respectively. Bivariate analysis revealed all fluoride exposure to be associated with reduced caries experience, but there were large correlations between some variables. When unconditional logistic regression analysis was used, the most important (p less than 0.05) odds ratios associated with no caries experience were for residence in a fluoridated area from four to 12 years of age and early use of toothpaste.(ABSTRACT TRUNCATED AT 250 WORDS)

Perceptions of dental fluorosis.

Mild dental fluorosis has long been accepted as a side-effect of water fluoridation and, more recently, has been recognized as a consequence of the use of other fluoride-based caries-preventive strategies. Traditionally, dental health professionals have not seen this as being of public health importance, but members of the public have not been asked their opinion. The purpose of the present study was to gather the opinions of lay groups concerning the appearance of the teeth of children with various degrees of fluorosis. Twenty-eight children, born in 1978, who had earlier participated in a study of fluorosis in Perth (Western Australia), allowed 110 observers to look at their upper central incisors under good viewing conditions. Fluorosis in these teeth ranged from TF score 0 (no fluorosis) to TF score 3. The observers were university students, parents, public servants, or dentists. They responded to statement items about the appearance of the teeth. The results, based on just over 3000 responses, showed that lay and dental observers could distinguish between different fluorosis levels. In response to a statement that the teeth appeared pleasing, a large majority agreed when the TF score was 0, but agreement declined as the TF score increased; when the TF score was 3, most people disagreed. Similarly, observers felt that the appearance would increasingly embarrass the child as the TF score increased. Observers, except the dentists, tended to feel that higher TF scores indicated neglect on the part of the child.(ABSTRACT TRUNCATED AT 250 WORDS)

Dental fluorosis and fluoride exposure in Western Australia.

Dental fluorosis in children is reported from many locations, and its prevalence may be increasing. This study aimed to measure fluorosis in 12-year-olds in fluoridated and non-fluoridated areas of Western Australia and to relate this to exposure. School dental clinics in Perth (F- 0.8 mg/L) and the Bunbury area (F- less than 0.2 mg/L) were the sampling units. Parents provided data on residence in fluoridated areas and on use of supplements and toothpaste. Exposure to water and supplemental fluoride between birth and four years was calculated. Clinical examinations (upper left central incisor) based on the TF classifications of fluorosis (which requires teeth to be dried) were conducted for 338 children in Perth and 321 in the Bunbury region. Re-examinations (n = 50) gave a weighted kappa of 0.78. Contingency analysis estimated bivariate relationships, and multiple logistic regression estimated odds ratios (OR) for risk factors. Fluorosis prevalence in the Perth region was 0.40, and in the Bunbury region 0.33 (chi 2 = 3.69, df = 1, p = 0.055). Prevalence was 0.44 in children with fluoride exposure equivalent to optimal water fluoridation and 0.20 among those with the lowest exposure (chi 2 = 35.99, df = 1, p = 0.0001). Increasing exposure was associated with higher fluorosis prevalence and higher TF scores, but overall, 27.3% of participants had TF score 1 (barely discernible), and only 9.4% had TF score greater than or equal to 2.(ABSTRACT TRUNCATED AT 250 WORDS)

Beta adrenoceptor blockade is associated with increased survival in male but not female hypertensive patients: a report from the DHSS Hypertension Care Computing Project (DHCCP).

The DHCCP is a multicentre observational study of patients being treated for hypertension in the United Kingdom. The influence of the type of anti-hypertensive therapy on survival was examined in 2,697 patients followed from 1971 with 206 deaths up to November 1981. Patients were classified by three types of treatment after one year in the project: betablockers (1,387), methyldopa (452) and others (667), (70% on diuretics only). The data were analysed both for all patients and for a subset excluding patients with previous ischaemic heart disease by all cause and IHD age-adjusted rates and life table analysis. Men on beta blockers had lower rates for total mortality, when compared with men on methyldopa (64% of the methyldopa rate, P less than 0.05) and when compared with men on other treatments (76% of the other treatment rate, P less than 0.1). The results for IHD mortality were similar. This improved survival of men in the beta blocker group was also found in the subset with no prior history of IHD. The benefit of beta blockers was not apparent in women: the lowest rates were observed for women on methyldopa, but the confidence limits for the ratios of relative rates were wide. Adjustment for blood pressure and cigarette smoking using the Cox proportional hazards model did not substantially modify the ratios of the mortality rates for the treatment groups. A sub-group analysis showed the reduction in all cause and IHD mortality associated with beta blockers was mainly due to the effect in non-smoking men.(ABSTRACT TRUNCATED AT 250 WORDS)

The relationship between a low treated blood pressure and IHD mortality: a report from the DHSS Hypertension Care Computing Project (DHCCP).

The suggestion that treating blood pressure to below a certain level may increase IHD mortality is controversial. We investigated the influence of treated blood pressure on mortality in the DHSS Hypertension Care Computer Project. Mortality was examined by quintiles of treated diastolic blood pressure (DBP) in 2,145 patients treated for a minimum period of one year and subsequently followed for an average of four years. One hundred and seventy five patients died; 71 from IHD. In men and women all cause mortality increased with level of treated DBP. In men IHD mortality showed a U-shaped distribution with an age-adjusted rate of 15.2 per 1,000 person years in the lowest fifth (DBP less than 86 mmHg) comparable to that of 15.6 per 1,000 in the upper (DBP greater than or equal to 103 mmHg). A similar pattern could not be established in women due to very few IHD deaths. IHD mortality was further examined separately for men by prior history of IHD. An increase in IHD deaths in the lowest fifth of treated blood pressure was found for men both with and without a history of IHD. No similar pattern of IHD mortality was obtained for untreated DBP or treated systolic pressure. However, we cannot exclude the possibility that the risk of low treated DBP is secondary to ischaemic heart disease.

The function of skin conductance response recovery and rise time.

The hypothesis that recovery time of the skin conductance response could be considered as a measure of attentional 'openness--closedness' to the environment was investigated by examining the relation of SCR recovery time to cardiac response variables established as measures of attentional stance. The hypothesis was not supported. However, rise time of SCR which is related to recovery time was found to be related to cardiac acceleration. It is suggested on the basis of these preliminary results that the measurement of SCR rise time should be undertaken in future studies.

Can organised dental care for children be both good and cheap?

Children's dental services evolved from emergency, pain-relieving and later amalgam-based care systems of the early and middle 20th century. The pattern of occurrence of dental caries is different today and young teenagers have very few teeth affected by caries. Restoration of lesions in permanent teeth, typically on occlusal or buccal/lingual surfaces, is technically simple. Paradoxically, dental students today are expected to master a vast amount of knowledge, including information on new dental materials and techniques. New dentists who choose to provide dental care for children as a career will spend most of their days placing fissure sealants, applying topical fluorides and inserting predominantly single-surface restorations. Because of their expensive training, new dentists will nevertheless expect high earnings, and this results in a high cost for children's dental care. The opportunity cost is other health services foregone. In developing countries where there are few dentists, they are almost not available for children at all. Costs could be reduced by reducing the number of interventions, and by reducing staff costs. Fewer interventions could be achieved by longer recall intervals: several studies and experience from places where this has been implemented indicate that is safe and effective. Widespread delegation of operative work to appropriately trained dental hygienists or therapists would reduce staff costs. Dental therapists are better substitutes for dentists in children's care because they are trained to do most of the clinical procedures that are necessary in children's dentistry. In Western Australia and South Australia, most dental care for children is provided by dental therapists. The costs of care are much lower and the outcome, as measured by caries experience and numbers of treated patients, is equivalent to or even better than European dentist-based services. Already, in some places, politicians and others are querying the need for organised children's dental care. Increased effectiveness will make continuation of children's dental services easier to sustain.

Fluoride supplements for young children: an analysis of the literature focusing on benefits and risks.

The use of fluoride supplements to prevent caries has been advised for more than 100 years, but serious promotion of this strategy occurred only after the effectiveness of water fluoridation was established, in the late 1950s and 1960s. Although the effectiveness of fluoride supplements was apparently endorsed by many small clinical studies, closer examination of the experimental conditions of these, their methods and the analysis of their results undermined confidence in their findings. It is likely that confounding resulted in spurious conclusions in many of them. More modern, well-conducted clinical trials of supplements suggest that today, in children also exposed to fluoride from other sources such as toothpaste, the marginal effect of fluoride supplements is very small. There is evidence that fluoride lozenges, designed to maximise any local effect, may have a small caries preventive effect, particularly in deciduous teeth. Overall, poor compliance makes fluoride supplements a poor public health measure. Supplement use by young children is associated with a substantial risk of dental fluorosis. Fluorosis is an issue about which the public is becoming concerned in several countries and this concern, if translated into opposition to all fluoride use, could jeopardise the most successful caries preventive aid we have. The potential for dental fluorosis, concern about the public's reaction to this, the poor effectiveness of supplements and the public's poor compliance with their use are persuasive arguments for a radical reduction in the use of supplements by young children. Recent changes in fluoride dosage schedules and deferment of the age of commencing the use of supplements, implemented in many countries, have followed from these concerns. Supplements formulated as lozenges maximise topical exposure of enamel to fluoride and such products may offer older children and some adults a way of maintaining an elevated fluoride level in saliva at times when toothbrushing is not practical.

Community dentistry in Nordic dental schools.

Approximately a decade after the first plans for the teaching of community dentistry were made in the Nordic countries, a questionnaire survey of Nordic dental schools was conducted to find out to what extent community dentistry subjects had been introduced in undergraduate curricula. Replies were received from the 12 dental schools in Denmark, Finland, Norway and Sweden. These schools admitted 915 students in 1982-83. Seven had a department of community dentistry, and at least two others had plans to start one. About 100 h of teaching were given on community dentistry subjects during the 5-yr course of study, mostly on the traditional subjects of epidemiology, statistics, law and ethics. In some schools health education and other behavioral sciences subjects received a large amount of curriculum time. Decisionmaking theory and political science were not reported taught at any school. Three departments had attached clinics, with widely differing functions. The Nordic textbook in community dentistry was widely used, and separate examinations were held in community dentistry at most schools. Full-time postgraduate courses were offered at three schools. Although schools in all four countries expected the number of dental students to decrease in coming years, several schools expected community dentistry to expand with regard to curriculum time and staff, in keeping with trends in other countries.