Biological monitoring of exposure to organophosphorus insecticides in a group of horticultural greenhouse workers.
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Exposure to selected organophosphorus insecticides (OPs), malathion, diazinon and acephate, was evaluated in a group of horticultural greenhouse workers. This was achieved through measurements of the cumulative urinary excretion time courses of specific and non-specific biomarkers over a 24 h period following the onset of work exposure. For malathion, the absorbed daily doses were estimated from the 24 h cumulative urinary amounts of the specific mono- and di-carboxylic acid metabolites (the sum of MCA and DCA) through the use of a kinetic model. The observed 24 h urinary levels were also compared with a biological reference value (BRV) of 57 nmol kg(-1) of body weight established in a previous work on the basis of a human no-observed-effect level exposure dose. Excretion values were found to be 2.5% or less of the BRV, suggesting a negligible health risk. Both median and 95th percentile concentrations of DCA (n = 57 samples) were, however, slightly higher than the baseline values determined by the Centers for Disease Control and Prevention (CDC) in the US civilian population (MCA was not analyzed by the CDC). The cumulative urinary excretion time course of the methyl phosphoric (MP) derivatives, which are metabolites of malathion but also of several other OPs, was also determined. Though relatively low, the MP levels were from 3 to 31 times higher than would be expected on the basis of the malathion specific MCA and DCA excretions, indicating that MP excretions stem from sources other than malathion exposure. Accordingly, only the time courses of MCA and DCA excretion rate (nmol h(-1)) were compatible with the time of work exposure. Urinary biomarkers of exposure to diazinon and acephate were also measured. Urinary concentrations were essentially below or equal to the analytical limit of detection of 1 microg l(-1) for 2-isopropyl-4-methyl-6-hydroxypyrimidine (n = 54) and of 0.8 microg l(-1) for acephate and methamidophos (n = 59): values within the baseline range of the US civilian population, like the observed phosphoric metabolite concentrations. The workers under study thus appeared to be only slightly more exposed to malathion than the general population. However, their overall exposure to OPs, as measured by non-specific phosphoric metabolites, was similar to that of the general population, whose exposure occurs mainly through the ingestion of contaminated food. These results question the relevance of measuring non-specific phosphoric metabolites when attempting to assess low-dose occupational exposure to a specific OP. (+info)
Does using potting mix make you sick? Results from a Legionella longbeachae case-control study in South Australia.
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A case-control study was performed in South Australia to determine if L. longbeachae infection was associated with recent handling of commercial potting mix and to examine possible modes of transmission. Twenty-five laboratory-confirmed cases and 75 matched controls were enrolled between April 1997 and March 1999. Information on underlying illness, smoking, gardening exposures and behaviours was obtained by telephone interviews. Recent use of potting mix was associated with illness (OR 4.74, 95% CI 1.65-13.55, P=0.004) in bivariate analysis only. Better predictors of illness in multivariate analysis included poor hand-washing practices after gardening, long-term smoking and being near dripping hanging flower pots. Awareness of a possible health risk with potting mix protected against illness. Results are consistent with inhalation and ingestion as possible modes of transmission. Exposure to aerosolized organisms and poor gardening hygiene may be important predisposing factors to L. longbeachae infection. (+info)
Diabetes on the Navajo nation: what role can gardening and agriculture extension play to reduce it?
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Diabetes has emerged as a serious health problem in the Navajo nation, the largest Indigenous tribe in the US. Persons with diabetes are at greater risk for developing other diseases such as cardiovascular disease. Navajos with diabetes almost certainly face a diminished quality of life if their diabetes is not managed properly. Aside from genetics, the incidence of diabetes is highly correlated with income, poor diet, and limited physical exercise. A review of the literature also implicates dietary shifts initiated by historical events and contemporary trends. Numerous studies have shown that moderate consumption of fruits and vegetables, combined with exercise, reduces the risk of or delays the onset of many diseases including diabetes. As part of a larger holistic approach, home and community garden projects have successfully addressed nutrition and food security issues on a grassroots scale. The Navajos have a tradition of farming and therefore expanding Navajo diabetes interventions to include the promotion of community and home gardens provides multiple opportunities. The benefits of these actions include: (i) a variety of nutritious food grown locally; (ii) physical activity attained through the act of daily gardening tasks; (iii) positive income garnered in terms of savings in food otherwise purchased at stores and excess produce canned, or if desired, sold at a farmer's market or trading post; and (iv) positive mental outlook through a combined sense of accomplishment at harvest time, bonding with the earth, and spiritual growth. The objectives of this article were to review the development of diabetes on the Navajo nation though historical and contemporary literature, to provide insight into the role of diet and exercise in the progression of the disease, and to offer cases and suggestions in the role that home and community gardening can play in diabetes reduction. A concluding discussion proposes a multidisciplinary approach to tackling diabetes on the Navajo nation involving public health officials, nutritionists, and horticultural extension agents that could also be applied internationally in similar multicultural, semi-arid climates. (+info)
Relationships between Mycobacterium isolates from patients with pulmonary mycobacterial infection and potting soils.
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High numbers of mycobacteria, including known pathogenic species such as Mycobacterium avium, Mycobacterium intracellulare, and Mycobacterium chelonae, were recovered from aerosols produced by pouring commercial potting soil products and potting soil samples provided by patients with pulmonary mycobacterial infections. The dominant mycobacteria in the soil samples corresponded to the dominant species implicated clinically. Profiles of large restriction fragments obtained by pulsed-field gel electrophoresis demonstrated a closely related pair of M. avium isolates recovered from a patient and from that patient's own potting soil. Thus, potting soils are potential sources of infection by environmental mycobacteria. Use of dust-excluding masks should be considered during potting or other activities that generate aerosol with soil. (+info)
Penetrating ocular injuries in the home.
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BACKGROUND: We studied the prevalence and aetiology of penetrating ocular injuries, in particular ones that were sustained whilst undertaking Do It Yourself (DIY) or gardening in the domestic environment. We also examined the extent of eye safety promotion in DIY stores and garden centres and on their websites. METHODS: We conducted a case note review of patients who underwent surgery for penetrating ocular trauma between January 2000 and June 2004. Eight DIY stores and garden centres and 10 websites were visited and evaluated using standardized questions. RESULTS: Of the 85 patients identified, 35 (41.2%) patients had injuries that occurred in the home with 10 patients having visual acuities of <6/60 at final follow up. Accidents from DIY or gardening were the cause in 17 of 33 (51.5%) patients, with a failure to wear eye protection in all cases. Overall, DIY stores and garden centres were poor at promoting eye safety both in their stores and on their websites. CONCLUSION: The home is a frequent place for severe penetrating ocular injury, with highly popular pastimes such as DIY and gardening as common causes. As many of these injuries are preventable, additional safety information is essential to educate the public on the potential dangers of these pastimes. (+info)
Time to pregnancy among female greenhouse workers.
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OBJECTIVES: Female greenhouse workers, who constitute a major occupational group exposed to pesticides at childbearing age, were studied to measure the effects of pesticide exposure on time to pregnancy. METHODS: Data were collected through postal questionnaires with detailed questions on time to pregnancy, lifestyle factors (eg, smoking habits, coffee and alcohol consumption), and worktasks (eg, application of pesticides, re-entry activities, and workhours) of the respondents and their partners in a 6-month period prior to conception of the most recent pregnancy. The relation between time to pregnancy and exposure to pesticides among 398 female greenhouse workers and 524 referents was studied in a Cox's proportional hazards model. RESULTS: The crude fecundability ratio for female greenhouse workers versus the reference group was 1.18 [95% confidence interval (95% CI) 1.03-1.35], but correction for confounding changed the fecundability ratio to 1.11 (95% CI 0.96-1.29). An evaluation of specific biases for time-to-pregnancy studies showed that these results were biased by the reproductively unhealthy worker effect. Restricting the analyses to full-time workers or first pregnancies only resulted in an adjusted fecundability ratio of 0.89 (95% CI 0.67-1.19) and 0.90 (95% CI 0.62-1.32), respectively. Among the primigravidous greenhouse workers, an association was observed between prolonged time to pregnancy and gathering flowers (fecundability ratio 0.46, 95% CI 0.18-1.19). CONCLUSIONS: This study may offer some evidence for the hypothesis of adverse effects of pesticide exposure on time to pregnancy, but more research is needed to elucidate these effects. (+info)
A novel method of supplying nutrients permits predictable shoot growth and root : shoot ratios of pre-transplant bedding plants.
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BACKGROUND AND AIMS: Growth of bedding plants, in small peat plugs, relies on nutrients in the irrigation solution. The object of the study was to find a way of modifying the nutrient supply so that good-quality seedlings can be grown rapidly and yet have the high root : shoot ratios essential for efficient transplanting. METHODS: A new procedure was devised in which the concentrations of nutrients in the irrigation solution were modified during growth according to changing plant demand, instead of maintaining the same concentrations throughout growth. The new procedure depends on published algorithms for the dependence of growth rate and optimal plant nutrient concentrations on shoot dry weight W(s) (g m(-2)), and on measuring evapotranspiration rates and shoot dry weights at weekly intervals. Pansy, Viola tricola 'Universal plus yellow' and petunia, Petunia hybrida 'Multiflora light salmon vein' were grown in four independent experiments with the expected optimum nutrient concentration and fractions of the optimum. Root and shoot weights were measured during growth. KEY RESULTS: For each level of nutrient supply W(s) increased with time (t) in days, according to the equation DeltaW(s)/Deltat=K(2)W(s)/(100+W(s)) in which the growth rate coefficient (K(2)) remained approximately constant throughout growth. The value of K(2) for the optimum treatment was defined by incoming radiation and temperature. The value of K(2) for each sub-optimum treatment relative to that for the optimum treatment was logarithmically related to the sub-optimal nutrient supply. Provided the aerial environment was optimal, R(sb)/R(o) approximately W(o)/W(sb) where R is the root : shoot ratio, W is the shoot dry weight, and sb and o indicate sub-optimum and optimum nutrient supplies, respectively. Sub-optimal nutrient concentrations also depressed shoot growth without appreciably affecting root growth when the aerial environment was non-limiting. CONCLUSION: The new procedure can predict the effects of nutrient supply, incoming radiation and temperature on the time course of shoot growth and the root : shoot ratio for a range of growing conditions. (+info)
Ethnobotany in the Cumbres de Monterrey National Park, Nuevo Leon, Mexico.
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BACKGROUND: An ethnobotanical study in the Cumbres de Monterrey National Park (CMNP), Nuevo Leon, Mexico was conducted. In spite of the large area (1,773.7 km2), heterogeneous physiography, contrasting plant communities and high species diversity of the CMNP, very little was previously known about its useful plants. Based on 95 interviews with inhabitants of the region who were 35 years old or older, we recorded ethnobotanical data of 240 species (comprising 170 genera and 69 botanical families), and 146 different uses. Most of the cited uses (98) were found to be medicinal ones. METHODS: Ninety five inhabitants 35 years old and oldest were interviewed to know what are the main plant uses in the Cumbres de Monterrey National Park. RESULTS AND DISCUSSION: Two hundred and forty species, 170 genera, and 69 families of useful plants and 146 different uses were recorded. We found most of the uses to be medicinal (98), while the rest (48) represent various purposes. Herbaceous plants are the most used, followed by shrubs and trees. (+info)