Past, Present, and Future of Integrated Control of Apple Pests: The New Zealand Experience.

This review describes the New Zealand apple industry's progression from 1960s integrated pest control research to today's comprehensive integrated pest management system. With the exception of integrated mite control implemented during the 1980s, pest control on apple crops was dominated by intensive organophosphate insecticide regimes to control tortricid leafrollers. Multiple pest resistances to these insecticides by the 1990s, and increasing consumer demand for lower pesticide residues on fruit, led to the implementation of integrated fruit production. This substantially eliminated organophosphate insecticide use by 2001, replacing it with pest monitoring systems, threshold-based selective insecticides, and biological control. More recently, new demands for ultralow-residue fruit have increased the adoption of mating disruption and use of biological insecticides. Widespread adoption of selective pest management has substantially reduced the status of previously important pests, including leafrollers, mealybugs, leafhoppers, and mites for improved phytosanitary performance, and contributed to major reductions in total insecticide use.

Regulatory Innovation, Mating Disruption and 4-Play(TM) in New Zealand.

Straight-chained lepidopteran pheromones are now regulated under a group standard in New Zealand, which is generic for moth pheromone products of similar low risk, under the Hazardous Substances and New Organisms Act (1996). This means that compliant new pheromone products can be developed and commercialized with low regulatory requirements. This encourages innovation and supports fruit industries interested in meeting export phytosanitary standards, while targeting low or nil residues of pesticides. Changes to pheromone blends for reasons such as technical improvements or variations in pest species composition in different crops can be made with minimal regulatory involvement. We illustrate how this system now operates with a four species mating disruption product commercialized in 2012. The odors involved in "4-Play™" consist of a range of components used by codling moth (Cydia pomonella), lightbrown apple moth (Epiphyas postvittana), green-headed leafroller (Planotortrix octo), and brown-headed leafroller (Ctenopseustis obliquana). The development of 4-Play™ illustrates how mating disruption of insects can support industry goals.

Overview of the National Occupational Mortality Surveillance (NOMS) system: leukemia and acute myocardial infarction risk by industry and occupation in 30 US states 1985-1999, 2003-2004, and 2007.

BACKGROUND: Cancer and chronic disease are leading causes of death in the US with an estimated cost of $46 billion. METHODS: We analyzed 11 million cause-specific deaths of US workers age 18-64 years in 30 states during 1985-1999, 2003-2004, and 2007 by occupation, industry, race, gender, and Hispanic origin. RESULTS: The highest significantly elevated proportionate leukemia mortality was observed in engineers, protective service, and advertising sales manager occupations and in banks/savings &loans/credit agencies, public safety, and public administration industries. The highest significantly elevated smoking-adjusted acute myocardial infarction mortality was noted in industrial and refractory machinery mechanics, farmers, mining machine operators, and agricultural worker occupations; and wholesale farm supplies, agricultural chemical, synthetic rubber, and agricultural crop industries. CONCLUSIONS: Significantly elevated risks for acute myocardial infarction and leukemia were observed across several occupations and industries that confirm existing reports and add new information. Interested investigators can access the NOMS website at http://www.cdc.gov/niosh/topics/NOMS/.

Occupational lung cancer in US women, 1984-1998.

BACKGROUND: Lung cancer is the leading cause of cancer death in US women, accounting for 72,130 deaths in 2006. In addition to smoking cessation, further reduction of the burden of lung cancer mortality can be made by preventing exposure to occupational lung carcinogens. Data for occupational exposures and health outcomes of US working women are limited. METHODS: Population-based mortality data for 4,570,711 women who died between 1984 and 1998 in 27 US States were used to evaluate lung cancer proportionate mortality over time by the usual occupation and industry reported on death certificates. Lung cancer proportionate mortality ratios were adjusted for smoking, using data from the National Health Interview Survey (NHIS) and the American Cancer Society's Cancer Prevention Study II. RESULTS: Analyses revealed that 194,382 white, 18,225 Black and 1,515 Hispanic women died 1984-1998 with lung cancer reported as the underlying cause of death. Following adjustment for smoking, significant excess proportionate lung cancer mortality was observed among US women working in the US manufacturing; transportation; retail trade; agriculture, forestry, and fishing; and nursing/personal care industries. Women employed in precision production, technical, managerial, professional specialty, and administrative occupations experienced some of the highest significantly excess proportionate lung cancer mortality during 1984-1998. CONCLUSIONS: The results of our study point to significantly elevated risks for lung cancer after adjustment for smoking among women in several occupations and industries. Because 6-17% of lung cancer in US males is attributable to known exposures to occupational carcinogens, and since synergistic interactions between cigarette smoke and other occupational lung carcinogens have been noted, it is important to continue research into the effects of occupational exposures on working men and women.

Confirming the Presence of Legionella pneumophila in Your Water System: A Review of Current Legionella Testing Methods.

Legionnaires' disease has been recognized since 1976 and Legionella pneumophila still accounts for more than 95% of cases. Approaches in countries, including France, suggest that focusing risk reduction specifically on L. pneumophila is an effective strategy, as detecting L. pneumophila has advantages over targeting multiple species of Legionella. In terms of assays, the historically accepted plate culture method takes 10 days for confirmed Legionella spp. results, has variabilities which affect trending and comparisons, requires highly trained personnel to identify colonies on a plate in specialist laboratories, and does not recover viable-but-non-culturable bacteria. PCR is sensitive, specific, provides results in less than 24 h, and determines the presence/absence of Legionella spp. and/or L. pneumophila DNA. Whilst specialist personnel and laboratories are generally required, there are now on-site PCR options, but there is no agreement on comparing genome units to colony forming units and action limits. Immunomagnetic separation assays are culture-independent, detect multiple Legionella species, and results are available in 24 h, with automated processing options. Field-use lateral flow devices provide presence/absence determination of L. pneumophila serogroup 1 where sufficient cells are present, but testing potable waters is problematic. Liquid culture most probable number (MPN) assays provide confirmed L. pneumophila results in 7 days that are equivalent to or exceed plate culture, are robust and reproducible, and can be performed in a variety of laboratory settings. MPN isolates can be obtained for epidemiological investigations. This accessible, non-technical review will be of particular interest to building owners, operators, risk managers, and water safety groups and will enable them to make informed decisions to reduce the risk of L. pneumophila.

Comparing Deliveries of Sterile Codling Moth (Lepidoptera: Tortricidae) by Two Types of Unmanned Aerial Systems and from the Ground.

New Zealand apple exports must meet strict phytosanitary measures to eliminate codling moth (Cydia pomonella Linnaeus) (Lepidoptera: Tortricidae) larval infestation. This study was part of a program attempting the localized eradication of codling moth within an isolated cluster of seven orchards (391 ha). A conventional management program of insecticide sprays and pheromone mating disruption was supplemented with weekly releases of sterile moths for 1-6 yr. Our objective was to compare the recapture rate of sterile moths following their release by four methods, and the efficiency of each system. The methods were the following: a fixed-wing unmanned plane flying ~40-45 m high at 70 km/h, an unmanned hexacopter travelling 20 m high at 25 km/h, and manually from the ground via bicycles or motor vehicles. The different release methods were used in different years or weeks. Sterile male moths were recaptured in grids of pheromone traps positioned throughout each orchard. The highest recapture rate followed delivery by hexacopter, then bicycle, vehicle, and plane. There was a 17-fold difference in catches between releases by hexacopter and plane, and sixfold between vehicle and plane in the same season. Bicycle delivery had a 3.5-fold higher recapture rate than the plane in different years. The wind-borne horizontal drift of moths was investigated as a possible explanation for the disparity of recaptures between the two aircraft delivery systems. The methods in ascending order of time per hectare for delivery were the following: plane and vehicle, hexacopter, then bicycle. The advantages and disadvantages of each moth delivery method are discussed.

Combined Effects of Mating Disruption, Insecticides, and the Sterile Insect Technique on Cydia pomonella in New Zealand.

Codling moth was introduced into New Zealand, and remains a critical pest for the apple industry. Apples exported to some markets require strict phytosanitary measures to eliminate the risk of larval infestation. Mating disruption and insecticide applications are the principal means of suppression in New Zealand. We tested the potential for the sterile insect technique (SIT) to supplement these measures to achieve local eradication or suppression of this pest. SIT was trialed in an isolated group of six integrated fruit production (IFP) orchards and one organic orchard (total 391 ha), using sterilized insects imported from Canada, with release by unmanned aerial vehicle and from the ground. Eradication was not achieved across the region, but a very high level of codling moth suppression was achieved at individual orchards after the introduction of sterile moths in combination with mating disruption and larvicides. After six years of releases, catches of wild codling moths at three IFP orchards (224 ha) were 90-99% lower than in 2013-2014, the year before releases began. Catches at three other IFP orchards (129 ha) decreased by 67-97% from the year before releases began (2015-2016), from lower initial levels. At a certified organic orchard with a higher initial population under only organic larvicides and mating disruption, by 2019-2020, there was an 81% reduction in wild moths capture from 2016-2017, the year before releases began.

Will Peri-Urban Cydia pomonella (Lepidoptera: Tortricidae) Challenge Local Eradication?

Codling moth, Cydia pomonella (Lepidoptera: Tortricidae), is a phytosanitary pest of New Zealand's export apples. The sterile insect technique supplements other controls in an eradication attempt at an isolated group of orchards in Hawke's Bay, New Zealand. There has been no attempt in New Zealand to characterize potential sources of uncontrolled peri-urban populations, which we predicted to be larger than in managed orchards. We installed 200 pheromone traps across Hastings city, which averaged 0.32 moths/trap/week. We also mapped host trees around the pilot eradication orchards and installed 28 traps in rural Ongaonga, which averaged 0.59 moths/trap/week. In Hastings, traps in host trees caught significantly more males than traps in non-host trees, and spatial interpolation showed evidence of spatial clustering. Traps in orchards operating the most stringent codling moth management averaged half the catch rate of Hastings peri-urban traps. Orchards with less rigorous moth control had a 5-fold higher trap catch rate. We conclude that peri-urban populations are significant and ubiquitous, and that special measures to reduce pest prevalence are needed to achieve area-wide suppression and reduce the risk of immigration into export orchards. Because the location of all host trees in Hastings is not known, it could be more cost-effectively assumed that hosts are ubiquitous across the city and the area treated accordingly.

Peri-Urban Community Attitudes towards Codling Moth Trapping and Suppression Using the Sterile Insect Technique in New Zealand.

New, more socially-acceptable technologies are being developed to suppress horticultural pests, because suppression is technically difficult with current technologies, especially in urban areas. One technique involves the release of sterile insects to prevent offspring in the next generation. This technology involves aerial or ground release systems, but this could also create issues for the public. This study investigated community perceptions of a recently-introduced response to codling moth control in New Zealand-Sterile Insect Technique (SIT). Community attitudes to SIT were examined in Hastings, New Zealand, in April, 2018. Eighty-six detailed interviews were undertaken with a random sample of households. This community was very willing (98% agreement) to host a sex pheromone trap in their gardens, and condoned regular visits to monitor traps. Attitudes to SIT were very positive (98% in favor). Once explained, the concept of using unmanned aerial vehicles to deliver sterile insects was also acceptable (98%) to the community. Use of unmanned aerial vehicles to release sterile insects during a hypothetical incursion response of an exotic fruit fly was also supported at 98% by respondent householders. Investigation of community attitudes can be valuable to guide practitioners in determining suitable technologies before an area-wide programme is launched.

Factors Responsible for Changes in Leafroller (Lepidoptera: Tortricidae) Species Composition on Orchards and Vineyards 1974-2015, in Hawke's Bay, New Zealand.

Leafrollers are polyphagous pests whose larvae damage fruit and cause market access problems for fruit crops exported from New Zealand. Leafroller larvae and pupae were collected mainly from four fruit crops, but also from hedges, ornamental trees, and understory weeds in orchards and vineyards of Hawke's Bay, a major fruit production region. Samples were collected from 1974 to 1977 and 1993 to 2015. This timespan was divided into periods that broadly coincided with broad-spectrum insecticide management, the transition to selective insecticides, and the full implementation of integrated fruit production (IFP) programs in apples, grapes, and stone fruit. Eight tortricid species were identified, but the accidentally introduced Epiphyas postvittana (Walker) (Lepidoptera: Tortricidae) and two native species, Ctenopseustis obliquana (Walker) and Planotortrix octo Dugdale, comprised 95% of the samples. The proportions of these three species varied according to interactions between four factors: pest management regime, collection period, property location, and host plant. In the 1970s under broad-spectrum insecticide programs, the native species dominated on all hosts. By the mid-late 1990s when IFP was introduced, all the main leafroller species were in decline. However, E. postvittana declined to a lesser extent than the two native species, and consequently, it became relatively more prominent. This change in species composition was delayed in two districts where localized cases of organophosphate insecticide resistance occurred in C. obliquana and P. octo. From 2000 onwards, E. postvittana was the dominant species in all districts and on all hosts, albeit with a much-reduced pest status, except on hedges and ornamental trees where C. obliquana prevailed.

Trapping Dasinuera mali (Diptera: Cecidomyiidae) in apples.

The midge Dasineura mali (Kieffer) (Diptera: Cecidomyiidae) is a significant pest of apples (Malus spp.), and the recent identification of the female sex pheromone is enabling new direct control tactics to be considered. Direct control using male suppression will require knowledge of the frequency of multiple mating, dispersal and colonization rates, and the efficiency of male removal. Males were able to mate up to five times, with a mean of 2.7 times when presented in a 10 female-to-1 male group, designed to simulate male suppression. Male catch in response to the pheromone loading was curvilinear over 4 orders of magnitude from 3 microg to 30 mg on rubber septa. Trapping using a high-dose pheromone lure was combined with oil-based traps similar to the inexpensive New Zealand "Lynfield trap" used for tephritid surveillance, to test male suppression in young orchard blocks at 500 traps per ha. Monitoring traps indicated 96% lower catch in the treated plots compared with control plots, over 137 d. However, a lack of shoot tip infestation in both treated and untreated plots indicated limited colonization and prevented an assessment of potential population suppression. Furthermore, a contribution to these results from communication disruption cannot be ruled out. Replicated transects of frequency of infested shoots from a mature orchard across the adjacent young block confirmed that colonization by ovipositing females was essentially limited to the first 30 m.

Methods to minimize the risks of Creutzfeldt-Jakob disease transmission by surgical procedures: where to set the standard?

New prion-related disorders have emerged over the past 20 years, of which the most notable in the human context is variant Creutzfeldt-Jakob disease (CJD). This disorder is a challenge to medical and public health professionals seeking early detection and diagnosis, provision of therapy, and support for persons affected and a better understanding of transmission risks. The risk of iatrogenic transmission of the disease remains a significant threat, given the well documented cases of CJD transmission via surgery, organ transplantation, and blood transfusion. This review discusses our current understanding of the prevalence of variant CJD, the distribution of tissue infectivity, and new methods for the decontamination of surgical instruments. A comparison of emerging technologies is provided on the basis of our current perception of surgical risk to identify methods that are likely to provide sufficient safety margins and to stimulate debate about the standards needed to protect against variant CJD and CJD transmission.

Injuries observed in a prospective transition from traditional to minimalist footwear: correlation of high impact transient forces and lower injury severity.

OBJECTIVES: Minimalist running is increasing in popularity based upon a concept that it can reduce impact forces and decrease injury rates. The purpose of this investigation is to identify the rate and severity of injuries in runners transitioning from traditional to minimalist footwear. The secondary aims were to identify factors correlated with injuries. METHODS: Fourteen habitually shod (traditional running shoes) participants were enrolled for this prospective study investigating injury prevalence during transition from traditional running shoes to 5-toed minimalist shoes. Participants were uninjured, aged between 22-41 years, and ran at least twenty kilometers per week in traditional running shoes. Participants were given industry recommended guidelines for transition to minimalist footwear and fit with a 5-toed minimalist running shoe. They completed weekly logs for identification of injury, pain using Visual Analogue Scale (VAS), injury location, and severity. Foot strike pattern and impact forces were collected using 3D motion analysis at baseline, 4 weeks, and 12 weeks. Injuries were scored according to a modified Running Injury Severity Score (RISS). RESULTS: Fourteen runners completed weekly training and injury logs over an average of 30 weeks. Twelve of 14 (86%) runners sustained injuries. Average injury onset was 6 weeks (range 1-27 weeks). Average weekly mileage of 23.9 miles/week prior to transition declined to 18.3 miles/week after the transition. The magnitude of the baseline impact transient peak in traditional shoes and in minimalist shoes negatively correlated with RISS scores (r = -0.45, p = 0.055 and r = -0.53, p = 0.026, respectively). CONCLUSION: High injury rates occurred during the transition from traditional to minimalist footwear. Non-compliance to transition guidelines and high injury rates suggest the need for improved education. High impact transient forces unexpectedly predicted lower modified RISS scores in this population.

Prospects for the control of apple leaf midge Dasineura mali (Diptera: Cecidomyiidae) by mass trapping with pheromone lures.

BACKGROUND: Apple leaf midge, Dasineura mali (Kieffer), poses quarantine issues for some apple export markets because larvae occasionally pupate in the stem end and calyx of fruit. Pheromone-baited oil-filled containers were used in 1 ha orchard plots to trap adult male D. mali in order to test the potential for mass trapping to reduce populations. RESULTS: Mass-trapped plots had 97% fewer adult males in pheromone traps and 48% fewer larvae per shoot in the second D. mali generation compared with untreated areas. Oil traps caught on average 900 000 D. mali per plot over 11 weeks during the second and third generations. Catches averaged 9200 per trap at plot corners. By comparison, catches were 51% lower 10-25 m away along borders, 80% lower at the midpoint of borders and 95% lower >7 m from plot edges. Fruit infestation was low (four out of 8000 apples). CONCLUSION: The attractiveness of the pheromone, monophagous habit and low mobility of D. mali enhance the prospects for successful mass trapping. Countering this are high populations, multivoltinism and aspects of mating behaviour. Mass trapping would probably have been more effective had it been in place season long and conducted over successive years. It needs refinements and more study before becoming a feasible control option for D. mali.

Heritable non-lethal damage to cultured human cells irradiated with heavy ions.

UNLABELLED: During interplanetary flights the nuclei of all of a crew member's cells could be traversed by at least one high-LET (Linear Energy Transfer) cosmic-ray particle. In mammalian cells irradiated in vitro about 1 in 10,000 of the surviving cells traversed by heavy particles is transformed to malignancy or mutated. What, if anything, happens to the remaining >99% of surviving cells? A retrospective analysis of archived data and samples from heavy-ion irradiation experiments with cultured human cells in vitro indicated that heavy ions caused a dose- and LET-dependent reduction in growth rates of progeny of irradiated cells, based on colony-size distributions. The maximum action cross section for this effect is between 100 and 300 microm2, at least as large as the cell nuclear area and up to 3 times the cross section for cell killing. Thus, heritable slow growth is the most prevalent effect of high-LET radiations on cultured animal cells, which may have implications for crew health during deep space travel. DISCLAIMER: The views expressed in this article are those of the author(s) and do not necessarily reflect the views or policies of the USEPA.

Antimicrobial effects of a novel Triclosan/zinc citrate dentifrice against mixed culture oral biofilms.

AIM: To compare the antimicrobial efficacy in vitro of a new fluoride system containing 0.3% Triclosan and 2.0% zinc citrate with a standard fluoride toothpaste against bacteria commonly isolated from dental plaque. METHOD: Mature biofilms of fixed depth containing ten oral bacterial species were developed in a model system and then exposed to the formulations both in situ and ex situ. RESULTS: The standard fluoride toothpaste had limited activity against the Gram positive species following 1 and 5 minutes ex situ exposure (p = 0.004 and p = 0.02, respectively) but none against the Gram negative species; also, no overall effect following repeated pulsing in situ was observed. In contrast, viable counts of Gram positive and Gram negative species were markedly reduced following ex situ exposure for 1 and 5 minutes to the new formulation (Gram positive: p = 0.0007 and p = 0.04; Gram negative: p = 0.04 and p = 0.00001, respectively). Counts of Gram positive bacteria were reduced by 99.9% over a 4-day in situ pulsing period, while no Gram negative species were recoverable from the biofilm by day 4. CONCLUSION: The new toothpaste formulation had a broad spectrum of antimicrobial activity against biofilm consortia containing bacteria associated with both dental caries and periodontal diseases.

Staphylococcus aureus dispersal from healthy volunteers.

BACKGROUND: Understanding Staphylococcus aureus dispersal from human carriers is vital for preventing transmission and colonization of this organism in health care settings. This study investigated the S aureus supershedder hypothesis in relation to attributes of healthy volunteers. METHODS: Microbial aerosol generation from volunteers was quantified within a controlled environmental chamber during walking or sitting activities. Biological air samplers were used to determine numbers of total S aureus colony-forming units disseminated during these activities. RESULTS: A total of 17 volunteers was sampled on 3 occasions. Hairstyle (long hair tied up or a shaved head) was the only significant predictor of dissemination of S aureus (5% significance level). No other significant effects were found at the 5% level. A negative binomial distribution provides the best fit with respect to S aureus. CONCLUSION: We found that, in the context of our small sample size, hairstyle (long hair tied up or a shaved head) statistically affected levels of bacteria shed from volunteers. However, we found no evidence for "supershedders" or "cloud adults," suggesting they are at an extreme end of a continuous distribution.

Occupational mortality associated with inflammatory bowel disease in the United States 1984-1998.

BACKGROUND: The occurrence of Crohn's disease (CD) and ulcerative colitis (UC) is shaped by environmental influences. Many such environmental risk factors vary potentially with occupational exposure. We used a large national database to study the occupational variation of mortality associated with CD and UC. METHODS: The National Occupational Mortality Surveillance database contains data from the death certificate linked with information about the occupation and industry of each deceased individual. Deaths were grouped by gender, ethnicity, disease type, occupation, and industry. Mortality by occupation and industry were expressed as age-adjusted proportional mortality ratio. RESULTS: A total of 3110 inflammatory bowel disease (IBD) patients were included in the present analysis. IBD mortality was low among blue collar workers and high among white collar workers. It was low among farming occupations, manufacturing occupations, and manual laborers. It was high among secretaries, professionals, sales workers, homemakers, managerial occupations, and teachers. There was a strong correlation between the occupational distribution of CD and UC that applied to men and women alike. The overall distribution among different industries corroborated the patterns observed with respect to the occupational distribution. CONCLUSIONS: The correlations between the occupational distribution of CD and UC support the contention that environmental influences shape the occurrence of both diseases. Such influence must vary by occupation and, to a lesser extent, also by industry. It must be similar for both types of IBD.

Bioassay studies support the potential for iatrogenic transmission of variant Creutzfeldt Jakob Disease through dental procedures.

BACKGROUND: Evidence is required to quantify the potential risks of transmission of variant Creutzfeldt Jakob (vCJD) through dental procedures. Studies, using animal models relevant to vCJD, were performed to address two questions. Firstly, whether oral tissues could become infectious following dietary exposure to BSE? Secondly, would a vCJD-contaminated dental instrument be able to transmit disease to another patient? METHODS: BSE-301V was used as a clinically relevant model for vCJD. VM-mice were challenged by injection of infected brain homogenate into the small intestine (Q1) or by five minute contact between a deliberately-contaminated dental file and the gingival margin (Q2). Ten tissues were collected from groups of challenged mice at three or four weekly intervals, respectively. Each tissue was pooled, homogenised and bioassayed in indicator mice. FINDINGS: Challenge via the small intestine gave a transmission rate of 100% (mean incubation 157±17 days). Infectivity was found in both dental pulp and the gingival margin within 3 weeks of challenge and was observed in all tissues tested within the oral cavity before the appearance of clinical symptoms. Following exposure to deliberately contaminated dental files, 97% of mice developed clinical disease (mean incubation 234±33 days). INTERPRETATION: Infectivity was higher than expected, in a wider range of oral tissues, than was allowed for in previous risk assessments. Disease was transmitted following transient exposure of the gingiva to a contaminated dental file. These observations provide evidence that dental procedures could be a route of cross-infection for vCJD and support the enforcement of single-use for certain dental instruments.

Potential occupational risks for neurodegenerative diseases.

BACKGROUND: Associations between occupations and neurodegenerative diseases (NDD) may be discernable in death certificate data. METHODS: Hypotheses generated from 1982 to 1991 study were tested in data from 22 states for the years 1992-1998. Specific occupations and exposures to pesticides, solvents, oxidative stressors, magnetic fields, and welding fumes were evaluated. RESULTS: About one third (26/87) of the occupations hypothesized with neurodegenerative associations had statistically significant elevated mortality odds ratios (MOR) for the same outcome. Occupations with the largest MORs were (a) for presenile dementia (PSD)-dentists, graders/sorters (non-agricultural), and clergy; (b) for Alzheimer's disease (AD)-bank tellers, clergy, aircraft mechanics, and hairdressers; (c) for Parkinson's disease (PD)-biological scientists, clergy, religious workers, and post-secondary teachers; and (d) for motor neuron disease (MND)-veterinarians, hairdressers, and graders and sorters (non-agricultural). Teachers had significantly elevated MORs for all four diseases, and hairdressers for three of the four. Non-horticultural farmers below age 65 had elevated PD (MOR = 2.23, 95% CI = 1.47-3.26), PSD (MOR = 2.22, 95% CI = 1.10-4.05), and AD (MOR = 1.76, 95% CI = 1.04-2.81). Sixty hertz magnetic fields exhibited significant exposure-response for AD and, below age 65, for PD (MOR = 1.87, 95% CI = 1.14-2.98) and MND (MOR = 1.63, 95% CI = 1.10-2.39). Welding had elevated PD mortality below age 65 (MOR = 1.77, 95% CI = 1.08-2.75). CONCLUSIONS: Support was observed for hypothesized excess neurodegenerative disease associated with a variety of occupations, 60 Hz magnetic fields and welding.