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Assessment of chemical exposure and self-reported health among tree planters in British ColumbiaGorman, Melanie Johanna 11 1900 (has links)
In British Columbia harvested forests are manually replanted by seasonal workers. Fertilizers contained in perforated paper sachets are often planted with seedlings. There have been anecdotal reports of skin and respiratory illness associated with fertilizer exposure and due to potential metal content in fertilizer source material they may contain metals as contaminants. Workers may also be exposed to pesticide residues on seedlings. This study aimed to characterize fertilizer, metal and pesticide exposure among a sample of B.C. tree planters, and to examine worker respiratory and dermal health.
Between May 2006 and April 2007 223 tree planters were interviewed about their respiratory and dermal health, and the exposures of 54 tree planters at five geographically-disperse worksites were monitored. Four worksites were using fertilizer and one was not. The health questionnaire was a modification of the American Thoracic Society standardized questionnaire with questions on dermal health taken from a previous UBC study. Workers were grouped in exposure categories and symptoms analysed using logistic regression. Metals were measured by ICP/MS on post shift hand wipes, full shift air sample filters, in whole blood, bulk soil, seedling root balls, and fertilizer samples. Pesticides were measured on post shift hand wipes and on bulk seedling samples. Using nursery pesticide application records, analyses focused on known pesticides applied to the seedlings at the study sites. Carbamate pesticides were analyzed by HPLC/MS and other pesticides by GC/MS.
No evidence was found that tree planters who work with fertilizer are at an elevated risk of exposure to arsenic, lead, cadmium, chromium and nickel relative to other tree planters. Pesticide residues were found on seedlings taken from coastal work sites in April 2007. At coastal worksites the fungicides chlorothalonil and iprodione were found on the skin of workers at low levels (range 0.37 – 106.3 ng.cm² and 0.48 – 15.9 ng/cm² respectively). Work with fertilizer was linked with an increased risk of cough, phlegm, nasal symptoms, nose bleed, and skin irritation. Hygiene conditions at tree planting work sites are very poor. Although measured exposures were low, hygiene conditions should improve to reduce the risk of health symptoms among tree planters. / Medicine, Faculty of / Population and Public Health (SPPH), School of / Graduate
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Assessment of the effects of toxic chemicals upon earthwormsGoats, Geoffrey Charles January 1985 (has links)
No description available.
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A cytogenetic study of the effects of pesticides.Wuu, Kuang-Dong January 1966 (has links)
No description available.
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Efficacy of bunamidine hydrochloride against immature and mature stages of Echinococcus granulosusJensen, Lauritz A. 11 December 1975 (has links)
A study was conducted to determine the efficacy of bunamidine hydrochloride against the immature and mature stages of Echinococcus granulosus found in Utah. Twenty-seven dogs were obtained from local animal shelters and experimentally infected with the parasite. The drug was given at dosage levels of 25 mg/kg to 50 mg/kg of bodyweight. It was from 85.9 to 98.8% effective against the immature stage, and 100% effective against the adult stage. The results suggest that this drug can feasibly be used under field conditions where hydatid disease is endemic.
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The effects of selected pesticides on microorganisms in terrestrial and aquatic environments.Charles, Norris C. January 1972 (has links)
No description available.
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A comparison of biomarkers in assessing the combined effects of pesticide mixtures on non-target soil invertebratesGola, Nontuthuzelo Pearl 12 1900 (has links)
Thesis (MSc)--University of Stellenbosch, 2004. / ENGLISH ABSTRACT: Agricultural environments are usually contaminated with mixtures of antropogenically
introduced chemicals as a result of pesticide spraying, which can affect beneficial, nontarget
soil invertebrates, such as earthworms negatively. Most studies on mixture toxicity
have focused on interactions of chemicals with similar structures and mechanisms.
However, chemical mixtures may occur as conglomerates of diverse structures and
toxicological mechanisms in the environment.
This study was aimed at assessing the effects of pesticides singly, and in a mixture, on
earthworms, using lifecycle parameters (growth and reproduction) and biomarkers
(neutral red retention (NRR) assay and acetylcholinesterase (AChE) inhibition) as
endpoints. Thus, to determine whether any interactions occurred between the pesticides
as shown by the measured endpoints. Another aim was to validate the use of the chosen
biomarkers for assessing mixture toxicity.
The pesticides used were from three groups: organophosphates, heavy metal-containing
pesticides and pyrethroids. From these three groups, four of the most commonly used
pesticides in the orchards and vineyards of the Western Cape, South Africa, were chosen,
namely chlorpyrifos (organophosphate), azinphos-methyl (organophosphate), copper
oxychloride (heavy metal-containing fungicide) and cypermethrin (pyrethroid).
Earthworms were exposed in the laboratory to a range of concentrations of chlorpyrifos
and copper oxychloride singly, and in 1:1 mixtures of these pesticides in artificial soil, for
four weeks. After the exposure period, the biomass change was determined as measure
of growth, and cocoon production, hatching success and number of hatchlings per cocoon
were determined as measures of reproduction.
Growth (biomass change) and reproduction (cocoon production) were affected by the
highest concentration treatment (20mg/kg) of chlorpyrifos, but copper oxychloride and
the mixture of the two pesticides showed no observable effects on lifecycle parameters.
Dose related effects on NRR times were however determined for both pesticides and the
mixture. Dose related effects on AChE activity were found for chlopyrifos and the
mixture of the two pesticides, but not for copper oxychloride. Short-term exposures (48
hours) of earthworms to the following pesticides in artificial groundwater: chlorpyrifos, copper oxychloride, azinphos-methyl, cypermethrin, chlorpyrifos-copper oxychloride,
chlorpyrifos -azinphos-methyl and chlorpyrifos-cypermethrin, were done followed by the
determination of AChE inhibition. Dose related effects were exhibited on the AChE
activity of earthworms exposed to chlorpyrifos, a mixture of chlorpyrifos and copper
oxychloride, azinphos-methyl, and a mixture of azinphos-methyl and chlorpyrifos.
Copper oxychloride, cypermethrin and the mixture of chlorpyrifos and cypermethrin had
no effect on AChE activity. Earthworms died at the highest exposure concentration of
the mixture of chlopyrifos and cypermethrin.
Results have shown that although the pesticides did not cause observable effects on
lifecycle parameters, there were effects at subcellular and biochemical level, as shown by
the biomarkers. Mixtures of pesticides, in some instances, affected earthworms
differently from their single components, indicating interactions between the pesticides in
mixtures, as shown by the measured endpoints. The NRR assay proved to be a good
general biomarker of soil contamination, and the AChE activity could also be a valuable
tool in assessing the effects of organophosphate mixtures and mixtures of
organophosphates and pesticides from other groups. / AFRIKAANSE OPSOMMING: Nie-teiken organismes, soos erdwurms, word negatief beïnvloed deur mengsels van
antropogeniese chemikalieë in landbou-omgewings. Die meeste studies wat handel oor
die toksisiteit van chemiese mengsels het tot dusver gefokus op chemikalieë van dieselfde
aard en met dieselfde meganismes van werking. Mengsels van chemiese stowwe kan
egter as konglomerate van 'n verskeidenheid strukturele eienskappe en met verskillende
toksiese meganismes in die omgewing aangetref word.
Tydens die studie is gepoog om die effekte van enkel pestisiede sowel as mengsels
daarvan op erdwurms te bestudeer, deur van lewensloop kenmerke (groei en
voortplanting) en biomerkers (neutraalrooi retensietyd - NNR en inhibisie van
asetielcholienesterase -AChE) as eindpunte gebruik te maak. 'n Verdere doel van die
studie was om vas te stel of daar enige wisselwerkings tussen die verskillende pestisiede
plaasvind, soos aangetoon deur die gemete eindpunte, en verder ook om die gebruik van
die gekose biomerkers as maatstawwe van mengseltoksisiteit te evalueer.
Die pestisiede wat gebruik is, is van drie verskillende groepe afkomstig: organofosfate,
swaarmetale en piretroiede. Van hierdie drie groepe is vier van die pestisiede wat vry
algemeen in boorde en wingerde in die Weskaap, Suid-Afrika, gebruik word,
geïdentifiseer. Hierdie stowwe is chlorpyrifos (organofosfaat), azinphos-metiel
(organofosfaat), koperoksichloried (swaarmetaalbevattende fungisied) en sipermetrien
(piretroied).
Erdwurms is in die laboratorium aan 'n reeks konsentrasies van chlorpyrifos en
koperoksichloried as enkel toksikante en as 1:1 mengsels in kunsmatige grond, vir vier
weke blootgestel. Voor en na die blootstellingsperiode is die biomassa van die wurms, as
maatstaf van groei, bepaal en kokonproduksie, uitbroeisukses en getal nakomelinge per
kokon bepaal as maatstawwe van voortplantingsvaardigheid. Groei
(biomassaverandering) en voortplanting (kokonproduksie) is beinvloed deur behandeling
met die hoogste konsentrasie (20 mg/kg) chlorpyrifos, terwyl geen effek van
koperoksichloried of die mengsel van hierdie twee pestisiede gevind is nie. Daar is gevind dat beide die pestisiede, enkel en in die mengsel, die NRR tye beinvloed het. Die
AChE aktiwiteit is beinvloed deur chlorpyrifos en die mengsel, maar nie deur die
koperoksichloried nie.
Korttermyn blootstellings van erdwurms (48 uur), in kunsmatige grondwater, van
erdwurms aan chlorpyrifos, koperoksichloried, azinphos-metiel en sipermetrien as enkel
toksikante en mengsels van chlorpyrifos-koperoksichloried, chlorpyrifos-azinphos-metiel
en chlorpyrifos-sipermetrien, is gedoen en gevolg deur die bepaling van AChE inhibisie.
Koperoksichloried, cypermetrien en die chlorpyrifos-sipermetrien mengsel het geen
waarneembare effek op die AChE aktiwiteit gehad nie ?????. Die erdwurms wat
blootgestel is aan die hoogste konsentrasie in die mengsel van chlorpyrifos-sipermetrien
het doodgegaan.
Die resultate het getoon dat die pestisiede nie in die korttermyn die lewensloopkenmerke
in enige waarneembare mate geaffekteer het nie maar daar was effekte op sellulêre en
biochemiese vlakke soos aangetoon deur die biomerkers. Sommige mengsels van die
pestisiede het die erdwurms verskillend van die enkelstowwe geaffekteer. Daar het dus
wisselwerking tussen sommige van die pestisiede wat in mengsels aangewend is,
plaasgevind, soos aangetoon deur die gemete eindpunte. Die NRR toets, as breë-spektrum
biomerker was 'n goeie maatstaf van kontaminasie in grond en daar is aanduidings dat
die AChE aktiwiteit, as 'n spesifieke biomerker, 'n nuttige maatstaf kan wees om die
effekte van organofosfaatmengsels en mengsels van hierdie chemiese groep en die van
ander chemikalieë aan te toon.
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An overview of pesticide consumption and management in Hong KongLam, Ding., 林鼎. January 2000 (has links)
published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management
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Evaluating space use and pesticide exposure risk for burrowing owls in an agricultural environmentGervais, Jennifer A. 22 April 2002 (has links)
Large burrowing owl (Aihene cunicularia) populations exist in areas of
intensive agriculture in California, and pesticide exposure has been identified as a
potential threat to population persistence. I evaluated breeding season use of
agricultural fields by adult male owls using radio telemetry, and examined egg
contaminant residues to estimate population-level effects on reproduction and
survival. Reproduction and survival were estimated annually, and an index of diet
was inferred from pellet samples. A total of 11 adult males in 1998 and 22 in 1999
were successfully radio-tracked. Mean fixed kernel home range sizes were 172 ha
(SE=68) in 1998 and 98 ha (SE=16) in 1999. Pellet analyses indicated a
substantial increase in the numbers of rodents consumed in 1999, associated with an
observed population explosion of California voles (Microtus calfornicus). Distance
to the nest was the most important factor in differentiating between foraging and
random locations, and there was no tendency to select or avoid any cover type.
Owls did forage in agricultural fields, but I failed to find evidence of selection or
avoidance of fields recently treated with pesticides. A total of 92 eggs were
collected over 5 years. Egg contaminants were generally limited to the presence of
p,p'DDE, which fluctuated by 4 orders of magnitude among years, from 0.05 ug/g
to 33 ug/g fresh weight p,p'DDE. There was a general pattern of decline in egg
residues over time for individual birds. The levels of p,p'DDE I documented did not
appear to have any effect on either productivity or survival of adult females, nor
were they clearly related to diet. I modeled the effects of various pesticide exposure
impacts on demographic rates and determined that exposure rates based on field
data would lead to relatively minor declines in population growth rate. An elasticity
analysis of burrowing owl demographic parameters revealed a variable pattern, but
generally indicated that factors influencing anyone of the demographic parameters
of burrowing owls can have a substantial impact on population growth rate. / Graduation date: 2002
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Empowerment and Sustainable Agriculture in Loma Linda, Guatemala : A qualitative study on contributions for empowerment by the local association in Loma LindaDobricic, Kristina January 2011 (has links)
This study is focused in a Guatemalan small village, Loma Linda, and on the local association ASODILL that is working for sustainable agriculture and alternative employment possibilities. Many rural areas throughout the world, including Guatemala, have been exposed to neglect by the government, political exclusion, and socioeconomic inequalities. The civil war that roared in Guatemala from 1960 to 1996 left behind psychological suffering, mistrust for the government, socioeconomic weakening and infrastructural destruction. Currently Guatemala suffers from rural poverty, environmental destruction and from an unaccountable state prioritizing economic before an environmentally sound alternative development. Presently, pesticides are encouraged by the Guatemalan government and sold below the market price. The pesticides are, however, destroying the soil and decreasing soil fertility to the point that it turns unusable for agriculture. There have been records of farmers protesting demanding change: requiring the government to halt environmental damaging actions and financial assistance for sustainable agriculture. I am examining if the local association, ASODILL, has contributed to a social, political and economic empowerment through their main objectives of sustainable agriculture and increasing employment alternatives Loma Linda. John Friedmanns Empowerment theory is the main helping device for understanding the empowerment effects of ASODILL in the village better. Ethnography as interpersonal method enabled me to construct a view on how the village has generally changed through the association, by participatory observation and interviews. The conclusion suggests that the association, through its work for sustainable development, has contributed to a social empowerment. This is mainly because Loma Linda already has the necessary prerequisites. With a stable social infrastructure ASODILLs external networking and expansion made the association grow which included them in a wider political community that aims for similar objective and thereby are politically empowered. The association has not yet achieved any economic empowerment. If a long-term empowerment is to be achieved the Guatemalan government must start to take the farmers political demand seriously or there is a risk that the local prosperity will not be long lasted.
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Honeybee Losses as Related to Crop Dusting with ArsenicalsMcGregor, S. E., Caster, A. B., Frost, Marvin H. Jr. 10 1900 (has links)
This item was digitized as part of the Million Books Project led by Carnegie Mellon University and supported by grants from the National Science Foundation (NSF). Cornell University coordinated the participation of land-grant and agricultural libraries in providing historical agricultural information for the digitization project; the University of Arizona Libraries, the College of Agriculture and Life Sciences, and the Office of Arid Lands Studies collaborated in the selection and provision of material for the digitization project.
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