Effects of Natura 2000 on nontarget bird and butterfly species based on citizen science data.

The European Union's Natura 2000 (N2000) is among the largest international networks of protected areas. One of its aims is to secure the status of a predetermined set of (targeted) bird and butterfly species. However, nontarget species may also benefit from N2000. We evaluated how the terrestrial component of this network affects the abundance of nontargeted, more common bird and butterfly species based on data from long-term volunteer-based monitoring programs in 9602 sites for birds and 2001 sites for butterflies. In almost half of the 155 bird species assessed, and particularly among woodland specialists, abundance increased (slope estimates ranged from 0.101 [SD 0.042] to 3.51 [SD 1.30]) as the proportion of landscape covered by N2000 sites increased. This positive relationship existed for 27 of the 104 butterfly species (estimates ranged from 0.382 [SD 0.163] to 4.28 [SD 0.768]), although most butterflies were generalists. For most species, when land-cover covariates were accounted for these positive relationships were not evident, meaning land cover may be a determinant of positive effects of the N2000 network. The increase in abundance as N2000 coverage increased correlated with the specialization index for birds, but not for butterflies. Although the N2000 network supports high abundance of a large spectrum of species, the low number of specialist butterflies with a positive association with the N2000 network shows the need to improve the habitat quality of N2000 sites that could harbor open-land butterfly specialists. For a better understanding of the processes involved, we advocate for standardized collection of data at N2000 sites.

Efectos de Natura 2000 sobre las Especies No Focales de Aves y Mariposas con Base en Datos de Ciencia Ciudadana Resumen La red Natura 2000 (N2000) de la Unión Europea está entre las redes internacionales más grandes de áreas protegidas. Uno de sus objetivos es asegurar el estado de un conjunto predeterminado de especies de aves y mariposas (focales). Sin embargo, las especies no focales también pueden beneficiarse con la N2000. Evaluamos cómo el componente terrestre de esta red afecta la abundancia de las especies de aves y mariposas no focales más comunes con base en los datos de programas de monitoreo voluntario a largo plazo en 9,602 sitios para aves y en 2,001 sitios para mariposas. En casi la mitad de las 155 especies de aves evaluadas, particularmente entre aquellas especies especialistas en zonas boscosas, la abundancia incrementó (los estimaciones de la pendiente variaron desde 0.101 [DS 0.042] hasta 3.51 [DS 1.30]) conforme incrementó la proporción del paisaje cubierto por sitios de la N2000. Esta relación positiva existió en 27 de las 104 especies de mariposas (con una variación de estimaciones desde 0.382 [DS 0.163] hasta 4.28 [DS 0.768]), aunque la mayoría de las especies de mariposas fueron generalistas. Cuando se consideraron las covarianzas de cobertura de suelo estas relaciones positivas no fueron evidentes para la mayoría de las especies, lo que significa que la cobertura de suelo puede ser una determinante de los efectos positivos de la red N2000. El incremento en la abundancia conforme aumentó la cobertura de la N2000 estuvo correlacionado con el índice de especialización de las aves, pero no el de las mariposas. Aunque la red N2000 sostiene la abundancia alta de un espectro amplio de especies, el bajo número de mariposas especialistas con una asociación positiva a la red N2000 demuestra la necesidad de mejorar la calidad del hábitat de los sitios N2000 que podrían albergar a mariposas especialistas de campo abierto. Para un mejor entendimiento de los procesos involucrados, promovemos una recolección estandarizada de datos en los sitios de la red N2000.

Potential and limits to unravel the genetic architecture and predict the variation of Fusarium head blight resistance in European winter wheat (Triticum aestivum L.).

Genome-wide mapping approaches in diverse populations are powerful tools to unravel the genetic architecture of complex traits. The main goals of our study were to investigate the potential and limits to unravel the genetic architecture and to identify the factors determining the accuracy of prediction of the genotypic variation of Fusarium head blight (FHB) resistance in wheat (Triticum aestivum L.) based on data collected with a diverse panel of 372 European varieties. The wheat lines were phenotyped in multi-location field trials for FHB resistance and genotyped with 782 simple sequence repeat (SSR) markers, and 9k and 90k single-nucleotide polymorphism (SNP) arrays. We applied genome-wide association mapping in combination with fivefold cross-validations and observed surprisingly high accuracies of prediction for marker-assisted selection based on the detected quantitative trait loci (QTLs). Using a random sample of markers not selected for marker-trait associations revealed only a slight decrease in prediction accuracy compared with marker-based selection exploiting the QTL information. The same picture was confirmed in a simulation study, suggesting that relatedness is a main driver of the accuracy of prediction in marker-assisted selection of FHB resistance. When the accuracy of prediction of three genomic selection models was contrasted for the three marker data sets, no significant differences in accuracies among marker platforms and genomic selection models were observed. Marker density impacted the accuracy of prediction only marginally. Consequently, genomic selection of FHB resistance can be implemented most cost-efficiently based on low- to medium-density SNP arrays.

Reported health conditions in animals residing near natural gas wells in southwestern Pennsylvania.

Natural gas extraction activities, including the use of horizontal drilling and hydraulic fracturing, may pose potential health risks to both human and animal populations in close proximity to sites of extraction activity. Because animals may have increased exposure to contaminated water and air as well as increased susceptibility to contaminant exposures compared to nearby humans, animal disease events in communities living near natural gas extraction may provide "sentinel" information useful for human health risk assessment. Community health evaluations as well as health impact assessments (HIAs) of natural gas exploration should therefore consider the inclusion of animal health metrics in their assessment process. We report on a community environmental health survey conducted in an area of active natural gas drilling, which included the collection of health data on 2452 companion and backyard animals residing in 157 randomly-selected households of Washington County, Pennsylvania (USA). There were a total of 127 reported health conditions, most commonly among dogs. When reports from all animals were considered, there were no significant associations between reported health condition and household proximity to natural gas wells. When dogs were analyzed separately, we found an elevated risk of 'any' reported health condition in households less than 1km from the nearest gas well (OR = 3.2, 95% CI 1.07-9.7), with dermal conditions being the most common of canine disorders. While these results should be considered hypothesis generating and preliminary, they suggest value in ongoing assessments of pet dogs as well as other animals to better elucidate the health impacts of natural gas extraction on nearby communities.

Bridging the gap between marker-assisted and genomic selection of heading time and plant height in hybrid wheat.

Based on data from field trials with a large collection of 135 elite winter wheat inbred lines and 1604 F1 hybrids derived from them, we compared the accuracy of prediction of marker-assisted selection and current genomic selection approaches for the model traits heading time and plant height in a cross-validation approach. For heading time, the high accuracy seen with marker-assisted selection severely dropped with genomic selection approaches RR-BLUP (ridge regression best linear unbiased prediction) and BayesCπ, whereas for plant height, accuracy was low with marker-assisted selection as well as RR-BLUP and BayesCπ. Differences in the linkage disequilibrium structure of the functional and single-nucleotide polymorphism markers relevant for the two traits were identified in a simulation study as a likely explanation for the different trends in accuracies of prediction. A new genomic selection approach, weighted best linear unbiased prediction (W-BLUP), designed to treat the effects of known functional markers more appropriately, proved to increase the accuracy of prediction for both traits and thus closes the gap between marker-assisted and genomic selection.

Relatedness severely impacts accuracy of marker-assisted selection for disease resistance in hybrid wheat.

The accuracy of genomic selection depends on the relatedness between the members of the set in which marker effects are estimated based on evaluation data and the types for which performance is predicted. Here, we investigate the impact of relatedness on the performance of marker-assisted selection for fungal disease resistance in hybrid wheat. A large and diverse mapping population of 1739 elite European winter wheat inbred lines and hybrids was evaluated for powdery mildew, leaf rust and stripe rust resistance in multi-location field trials and fingerprinted with 9 k and 90 k SNP arrays. Comparison of the accuracies of prediction achieved with data sets from the two marker arrays revealed a crucial role for a sufficiently high marker density in genome-wide association mapping. Cross-validation studies using test sets with varying degrees of relationship to the corresponding estimation sets revealed that close relatedness leads to a substantial increase in the proportion of total genotypic variance explained by the identified QTL and consequently to an overoptimistic judgment of the precision of marker-assisted selection.

Optimum design of family structure and allocation of resources in association mapping with lines from multiple crosses.

Family mapping is based on multiple segregating families and is becoming increasingly popular because of its advantages over population mapping. Athough much progress has been made recently, the optimum design and allocation of resources for family mapping remains unclear. Here, we addressed these issues using a simulation study, resample model averaging and cross-validation approaches. Our results show that in family mapping, the predictive power and the accuracy of quatitative trait loci (QTL) detection depend greatly on the population size and phenotyping intensity. With small population sizes or few test environments, QTL results become unreliable and are hampered by a large bias in the estimation of the proportion of genotypic variance explained by the detected QTL. In addition, we observed that even though good results can be achieved with low marker densities, no plateau is reached with our full marker complement. This suggests that higher quality results could be achieved with greater marker densities or sequence data, which will be available in the near future for many species.

Comparison of biometrical models for joint linkage association mapping.

Joint linkage association mapping (JLAM) combines the advantages of linkage mapping and association mapping, and is a powerful tool to dissect the genetic architecture of complex traits. The main goal of this study was to use a cross-validation strategy, resample model averaging and empirical data analyses to compare seven different biometrical models for JLAM with regard to the correction for population structure and the quantitative trait loci (QTL) detection power. Three linear models and four linear mixed models with different approaches to control for population stratification were evaluated. Models A, B and C were linear models with either cofactors (Model-A), or cofactors and a population effect (Model-B), or a model in which the cofactors and the single-nucleotide polymorphism effect were modeled as nested within population (Model-C). The mixed models, D, E, F and G, included a random population effect (Model-D), or a random population effect with defined variance structure (Model-E), a kinship matrix defining the degree of relatedness among the genotypes (Model-F), or a kinship matrix and principal coordinates (Model-G). The tested models were conceptually different and were also found to differ in terms of power to detect QTL. Model-B with the cofactors and a population effect, effectively controlled population structure and possessed a high predictive power. The varying allele substitution effects in different populations suggest as a promising strategy for JLAM to use Model-B for the detection of QTL and then to estimate their effects by applying Model-C.

Bird population declines and species turnover are changing the acoustic properties of spring soundscapes.

Natural sounds, and bird song in particular, play a key role in building and maintaining our connection with nature, but widespread declines in bird populations mean that the acoustic properties of natural soundscapes may be changing. Using data-driven reconstructions of soundscapes in lieu of historical recordings, here we quantify changes in soundscape characteristics at more than 200,000 sites across North America and Europe. We integrate citizen science bird monitoring data with recordings of individual species to reveal a pervasive loss of acoustic diversity and intensity of soundscapes across both continents over the past 25 years, driven by changes in species richness and abundance. These results suggest that one of the fundamental pathways through which humans engage with nature is in chronic decline, with potentially widespread implications for human health and well-being.

Molecular marker assisted broadening of the Central European heterotic groups in rye with Eastern European germplasm.

Broadening the genetic base of heterotic pools is a key to ensure continued genetic gains in hybrid breeding and extend hybrid cultivation to new areas. In the present study, two Central European heterotic pools (Carsten and Petkus) and five Eastern European open-pollinated varieties (OPVs, Pop-1 to Pop-5) were studied with the objectives to (1) investigate the genetic diversity in OPVs and the heterotic pools using molecular and field data, (2) evaluate the molecular diversity among OPVs, (3) examine the combining ability for grain yield of the OPVs when crossed with testers in field trials, and (4) develop a strategy for targeted introgression of OPV germplasm into the heterotic pools. In total, 610 S(0) plants, 347 from OPVs and 263 from heterotic pools, were developed. Clones of the S(0) plants of OPVs were crossed with two testers belonging to each heterotic pool, while clones of heterotic pools were crossed with only the opposite tester. Testcrosses were evaluated for grain yield in multi-location trials. In addition, 589 S(0) plants were fingerprinted with 30 SSR markers. The data revealed that the Carsten pool has a narrow genetic base and should be the primary target for broadening the established heterotic pattern. Mean and genetic variance suggested that Pop-2 and Pop-4 are good candidates for introgression in Petkus pool and Pop-5 in Carsten pool. Nevertheless, introgression of Pop-5 in Carsten could reduce the genetic diversity between heterotic pools. Therefore, we suggest that either selected plants of Pop-5 should be introgressed or more Eastern European germplasm should be fingerprinted and field evaluated to identify promising germplasm for broadening the established heterotic pattern.

High-resolution investigations of ripple structures formed by femtosecond laser irradiation of silicon.

We report on the structural investigation of self-organized periodic microstructures (ripples) generated in Si(100) targets after multishot irradiation by approximately 100-fs to 800-nm laser pulses at intensities near the single shot ablation threshold. Inspection by surface sensitive microscopy, e.g., atomic force microscopy (AFM) or scanning electron microscopy (SEM), and conventional and high-resolution transmission electron microscopy reveal complex structural modifications upon interaction with the laser: even well outside the ablated area, the target surface exhibits fine ripple-like undulations, consisting of alternating crystalline and amorphous silicon. Inside the heavily modified area, amorphous silicon is found only in the valleys but not on the crests which, instead, consist of highly distorted crystalline phases, rich in defects.

Impact of interpopulation divergence on additive and dominance variance in hybrid populations.

We present a theoretical proof that the ratio of the dominance vs. the additive variance decreases with increasing genetic divergence between two populations. While the dominance variance is the major component of the variance due to specific combining ability (sigma(SCA)(2)), the additive variance is the major component of the variance due to general combining ability (sigma(GCA)(2)). Therefore, we conclude that interpopulation improvement becomes more efficient with divergent than with genetically similar heterotic groups, because performance of superior hybrids can be predicted on the basis of general combining ability effects.

Maternal exposure to water disinfection by-products during gestation and risk of hypospadias.

BACKGROUND: The use of chlorine for water disinfection results in the formation of numerous contaminants called disinfection by-products (DBPs), which may be associated with birth defects, including urinary tract defects. METHODS: We used Arkansas birth records (1998-2002) to conduct a population-based case-control study investigating the relationship between hypospadias and two classes of DBPs, trihalomethanes (THM) and haloacetic acids (HAA). We utilised monitoring data, spline regression and geographical information systems (GIS) to link daily concentrations of these DBPs from 263 water utilities to 320 cases and 614 controls. We calculated ORs for hypospadias and exposure to DBPs between 6 and 16 weeks' gestation, and conducted subset analyses for exposure from ingestion, and metrics incorporating consumption, showering and bathing. RESULTS: We found no increase in risk when women in the highest tertiles of exposure were compared to those in the lowest for any DBP. When ingestion alone was used to assess exposure among a subset of 40 cases and 243 controls, the intermediate tertiles of exposure to total THM and the five most common HAA had ORs of 2.11 (95% CI 0.89 to 5.00) and 2.45 (95% CI 1.06 to 5.67), respectively, compared to women with no exposure. When exposure to total THM from consumption, showering and bathing exposures was evaluated, we found an OR of 1.96 (95% CI 0.65 to 6.42) for the highest tertile of exposure and weak evidence of a dose-response relationship. CONCLUSIONS: Our results provide little evidence for a positive relationship between DBP exposure during gestation and an increased risk of hypospadias but emphasise the necessity of including individual-level data when assessing exposure to DBPs.

Chilling tolerance of Central European maize lines and their factorial crosses.

BACKGROUND AND AIMS: Chilling-stress tolerance is a prerequisite for maize production under cool climatic conditions. The main goal of this study was to evaluate the Central European dent and flint pools for chilling tolerance during heterotrophic and early autotrophic growth in field trials and growth chamber experiments. METHODS: Five European flint and five dent inbreds and their 25 factorial crosses were evaluated in six natural environments, where chilling occurred, for chlorophyll concentration and plant height at the three-leaf stage, and plant height and fresh weight at the seven-leaf stage. In growth chambers, leaf 3 growth was analysed under cold and control conditions. KEY RESULTS: Comparing the field and growth chamber data, the strongest association was found between leaf elongation rate during cold nights and plant height at the three-leaf stage, with a weaker association with the seven-leaf stage. In the field, moderate correlations were observed between plant height at the three-leaf stage, and plant height and fresh weight at the seven-leaf stage, respectively. Furthermore, mid-parent and hybrid performance were only moderately correlated. CONCLUSIONS: The results suggest that heterotrophic and early autotrophic growth stages are controlled by different genetic factors or that maternal effects play a role. In addition, the findings showed that mid-parent performance is a poor predictor of hybrid performance. Consequently, test cross performance should be the target in quantitiative trait locus (QTL) mapping studies with the final goal of establishing marker-assisted breeding programmes for chilling-tolerant hybrids.

Identifying public water facilities with low spatial variability of disinfection by-products for epidemiological investigations.

BACKGROUND AND AIMS: Epidemiological studies of disinfection by-products (DBPs) and reproductive outcomes have been hampered by misclassification of exposure. In most epidemiological studies conducted to date, all persons living within the boundaries of a water distribution system have been assigned a common exposure value based on facility-wide averages of trihalomethane (THM) concentrations. Since THMs do not develop uniformly throughout a distribution system, assignment of facility-wide averages may be inappropriate. One approach to mitigate this potential for misclassification is to select communities for epidemiological investigations that are served by distribution systems with consistently low spatial variability of THMs. METHODS AND RESULTS: A feasibility study was conducted to develop methods for community selection using the Information Collection Rule (ICR) database, assembled by the US Environmental Protection Agency. The ICR database contains quarterly DBP concentrations collected between 1997 and 1998 from the distribution systems of 198 public water facilities with minimum service populations of 100,000 persons. Facilities with low spatial variation of THMs were identified using two methods; 33 facilities were found with low spatial variability based on one or both methods. Because brominated THMs may be important predictors of risk for adverse reproductive outcomes, sites were categorised into three exposure profiles according to proportion of brominated THM species and average TTHM concentration. The correlation between THMs and haloacetic acids (HAAs) in these facilities was evaluated to see whether selection by total trihalomethanes (TTHMs) corresponds to low spatial variability for HAAs. TTHMs were only moderately correlated with HAAs (r = 0.623). CONCLUSIONS: Results provide a simple method for a priori selection of sites with low spatial variability from state or national public water facility datasets as a means to reduce exposure misclassification in epidemiological studies of DBPs.

Canine exposure to herbicide-treated lawns and urinary excretion of 2,4-dichlorophenoxyacetic acid.

A recent study by Hayes et al. (J. Natl. Cancer. Inst., 83: 1226-1231, 1991) found an increased risk of malignant lymphoma associated with exposure to 2,4-dichlorophenoxyacetic acid (2,4-D) in pet dogs. We conducted a study to determine the extent to which dogs absorb and excrete 2,4-D in urine after contact with treated lawns under natural conditions. Among 44 dogs potentially exposed to 2,4-D-treated lawns an average of 10.9 days after application, 2,4-D concentrations greater than or equal to 10.0 micrograms/l were found in 33 dogs (75%) and concentrations of > or = 50 micrograms/l were found in 17 (39%). Among 15 dogs with no known exposure to a 2,4-D-treated lawn in the previous 42 days, 4 (27%) had evidence of 2,4-D in urine, 1 at a concentration of > or = 50 micrograms/l. The odds ratio for the association between exposure to a 2,4-D-treated lawn and the detection of > or = 50 micrograms/l 2,4-D in urine was 8.8 (95% confidence interval, 1.4-56.2). Dogs exposed to lawns treated within 7 days before urine collection were more than 50 times as likely to have 2,4-D at concentrations > or = 50 micrograms/l than dogs with exposure to a lawn treated more than 1 week previously (odds ratio = 56.0; 95% confidence interval, 10.0-312.2). The highest mean concentration of 2,4-D in urine (21.3 mg/l) was found in dogs sampled within 2 days after application of the herbicide.(ABSTRACT TRUNCATED AT 250 WORDS)

Reproductive and developmental effects of disinfection by-products in drinking water.

Recent epidemiologic studies have reported associations between the consumption of chlorinated drinking water and reproductive and developmental effects. Here we review the available epidemiologic data, assess the hazard potential posed by exposure to disinfection by-products, identify critical data gaps, and offer recommendations for further research. The epidemiologic evidence supporting associations between exposure to water disinfection by-products (DBPs) and adverse pregnancy outcomes is sparse, and positive findings should be interpreted cautiously. The methods used during the early stages of research in this area have been diverse. Variability in exposure assessment and endpoints makes it difficult to synthesize or combine the available data. Exposure misclassification and unmeasured confounding may have lead to bias in risk estimation. Future studies of reproductive outcome and exposure to chlorinated water should use improved methods for exposure assessment to 1) assure selection of appropriate exposure markers, 2) assess seasonal and annual fluctuations in DBPs, 3) assess variability within the distribution system, and 4) assess exposure through multiple routes such as bathing and showering, as well as consumption. Population-based studies should be conducted to evaluate male and female fertility, conception delay, growth retardation, and specific birth defects. The reproductive and developmental effects of exposure to DBPs could be efficiently explored in ongoing investigations by incorporating valid exposure markers and relevant questionnaire information. Future studies should make use of naturally occurring variability in the concentrations of DBPs and may incorporate biomarkers of exposure and effect in their design. Epidemiologic investigations should be conducted in parallel with laboratory-based and animal studies in a coordinated, multidisciplinary approach.

Animals as sentinels of human health hazards of environmental chemicals.

A workshop titled "Using Sentinel Species Data to Address the Potential Human Health Effects of Chemicals in the Environment," sponsored by the U.S. Army Center for Environmental Health Research, the National Center for Environmental Assessment of the EPA, and the Agency for Toxic Substances and Disease Registry, was held to consider the use of sentinel and surrogate animal species data for evaluating the potential human health effects of chemicals in the environment. The workshop took a broad view of the sentinel species concept, and included mammalian and nonmammalian species, companion animals, food animals, fish, amphibians, and other wildlife. Sentinel species data included observations of wild animals in field situations as well as experimental animal data. Workshop participants identified potential applications for sentinel species data derived from monitoring programs or serendipitous observations and explored the potential use of such information in human health hazard and risk assessments and for evaluating causes or mechanisms of effect. Although it is unlikely that sentinel species data will be used as the sole determinative factor in evaluating human health concerns, such data can be useful as for additional weight of evidence in a risk assessment, for providing early warning of situations requiring further study, or for monitoring the course of remedial activities. Attention was given to the factors impeding the application of sentinel species approaches and their acceptance in the scientific and regulatory communities. Workshop participants identified a number of critical research needs and opportunities for interagency collaboration that could help advance the use of sentinel species approaches.

A cancer registry-based study of occupational risk for lymphoma, multiple myeloma and leukaemia.

Mortality and incidence studies have suggested that agricultural workers may be at increased risk for some cancers. Case-control methods were used to investigate the relationship between farming, other occupations, and lymphoma, multiple myeloma, and leukaemia. A total of 475 male cases, aged 20 years or more, and 1425 age-matched controls were identified through the Missouri Cancer Registry for the years 1984-1985. People with smoking-related cancers were excluded as controls to minimize bias associated with farmers' reported smoking patterns. Farmers had slightly elevated risks for non-Hodgkin's lymphoma (odds ratio (OR) = 1.11) and Hodgkin's disease (OR = 1.30). The risk for leukaemia (all types) was not elevated (OR = 0.91); however, for acute lymphatic leukaemia an OR of 2.84 was detected. An OR of 2.78 (95% confidence interval = 1.09-7.07) for reticulosarcoma was observed among farmers 65 years and older. Several other occupational associations were noted which have been reported previously. Carpenters (OR = 3.10) and machinists (OR = 4.85) were at increased risk for Hodgkin's disease. An elevated risk of leukaemia was observed for mechanics (OR = 4.79). Since most previous studies of the associations between lymphatic and haematopoietic cancers and agriculture have been based on mortality data, additional studies of incident cases are suggested.

Case-control studies of cancer in New Zealand electrical workers.

A series of reports, including a New Zealand case-control study, have suggested that electrical workers are at increased risk of leukaemia. We report here a further series of case-control studies based on the New Zealand Cancer Registry. These involved 19,904 male patients registered with cancer for the period 1980-1984 who were aged 20 years or more at time of registration. For each cancer site, the registrations for other sites formed the control group. Three main findings emerged. First, there is an elevated leukaemia risk in New Zealand electrical workers (odds ratio (OR) = 1.62, 95% confidence interval (Cl) 1.04-2.52), but little evidence of increased risks for other cancer sites. Second, contrary to other published studies, the increased risk was primarily for chronic leukaemia (OR = 2.12) rather than acute leukaemia (OR = 1.25), and for lymphatic leukaemia (OR = 1.73) rather than myeloid leukaemia (OR = 1.22). Third, the increased risk was strongest for certain categories of electrical work including radio and television repairers (OR = 7.86, 95% CI 2.20-28.09), electricians (OR = 1.68, 95% Cl = 0.75-3.79), linemen (OR = 2.35, 95% Cl 0.97-5.70) and power station operators (OR = 3.89, 95% Cl 1.00-15.22).

Cancer risks in New Zealand farmers.

Previous New Zealand case-control studies have found increased risk for leukaemia, non-Hodgkin's lymphoma (NHL) and multiple myeloma in farmers. We report here a further series of New Zealand Cancer Registry based case-control studies of farming and site-specific cancer risks. These involved 19,904 males aged 20 years or more who were registered with cancer between 1980 and 1984. For each cancer site, the registrations for other sites formed the control group. Farmers had elevated risks for malignant melanoma (Odds Ratio [OR] = 1.25, 95% confidence interval [Cl] 1.05-1.50), and for cancer of the lip (OR = 2.43, 95% Cl 1.81-3.27), rectum (OR = 1.19, 95% Cl 1.03-1.38), bone (OR = 1.95, 95% Cl 1.00-3.80), prostate (OR = 1.26, 95% Cl 1.13-1.41) and brain (OR = 1.34, 95% Cl 1.04-1.74). Decreased risks were observed for cancer of the larynx (OR = 0.66, 95% Cl 0.45-0.96), lung (OR = 0.70, 95% Cl 0.63-0.77) and testis (OR = 0.58, 95% Cl 0.39-0.88). Livestock farmers had a relatively high risk for brain cancer, while the risk for cancer of the lip was highest among dairy farmers. Farmers also had increased risks for cancer of the lymphatic and haematopoietic system (International Classification of Disease 9th edn (ICD) 200-208) (OR = 1.24, 95% Cl 1.08-1.42), leukaemia (OR = 1.24, 95% Cl 0.99-1.55) and non-Hodgkin's lymphoma (NHL) (OR = 1.24, 95% Cl 0.99-1.56), as described previously.