PubMed · 9867457
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F Orejuela, L I Lipshultz, D J Lamb. 1998. Debate about sperm count decline.. https://doi.org/10.1289/ehp.106-1533223
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The concentrations of herbicides in water from wetlands on landscapes where herbicides are not used should be less than on farms with moderate (conventional farms) and intense (minimum-till farms) herbicide use. In general, this hypothesis was not supported for wetlands situated in the Boreal Plains Ecozone of central Saskatchewan, Canada. The overall detection frequency of 10 commonly used herbicides was not significantly different among wildlife habitat with no pesticide use (44.4%), farms with no pesticide use (51.6%), conventional farms (54.9%), and minimum-till farms (56.5%, chi 2 = 5.64, p = 0.13). The herbicides (4-chloro-2-methylphenoxy) acetic acid (MCPA), 2,4-dichlorophenoxyacetic acid (2,4-D), bromoxynil, dicamba, mecoprop, and diclorprop accounted for 87% of all detections. In general, detection frequencies and concentrations of individual herbicides were similar on all land-use types. For example, the mean concentration of 2,4-D in water on the four land types ranged from 0.12 +/- 0.104 to 0.26 +/- 0.465 microgram/L, and MCPA ranged from 0.08 +/- 0.078 to 0.19 +/- 0.166 microgram/L. However, in the year of application, mean concentrations of MCPA and bromoxynil, but not 2,4-D, were significantly higher by about twofold in wetlands situated in fields where these herbicides were applied compared with all other wetlands. We propose that many agricultural pesticides are rapidly lost to the atmosphere at the time of application by processes such as volatilization from soil and plant evapotranspiration. Then, the herbicides used throughout the region may be directly absorbed to the surface of wetlands from the atmosphere, or they become entrained in local convective clouds, and are redistributed by rainfall in a relatively homogenous mixture over the agricultural landscape. The low levels of individual herbicides we found in most of the wetland waters would not cause chronic effects to aquatic biota.
Techniques for conventional forest soil surveys in Taiwan need to be further developed in order to save time and money. Although some soil-landscape regression models have been developed to describe and predict soil properties and depths, they have seldom been studied in Taiwan. This study establishes linear soil-landscape regression models related to soil depths and landscape factors found in the forest soils of southern Taiwan. These models were evaluated by validating the models according to their mean errors and root mean square errors. The study was carried out at the 60,000 ha Chishan Forest Working Circle. About 310 soil pedons were collected. The landscape factors included elevation, slope, aspect, and surface stone contents. Sixty percent of the total field samples were used to establish the soil-landscape regression models, and forty % were used for validation. The sampling strategy indicated that each representative pedon covers an area of about 147 ha. The number of samples was appropriate considering the available time and budget. The single variate and/or multivariate linear regression soil-landscape models were successfully established. Those models revealed significant inter-relations among the soil depths of the B and B+BC horizons, solum thickness, and landscape factors, including slope and surface stone contents (p < 0.003). The mean errors in the validation of the soil-landscape model were low and acceptable for this case study. In addition, the slope data derived from the DEM (digital elevation model) database in this case study were used to predict the soil depths of the B, B+BC horizons and the solum thickness without carrying out a field survey. Surface stone should be collected in a field soil survey to increase the precision of soil depth prediction of the B and B+BC horizons, and the solum thickness.
BACKGROUND: The purpose of the current study was to determine the distribution and relative frequency of each subtype of malignant lymphoma in southern Taiwan according to the revised European-American classification of lymphoid neoplasms (REAL). METHODS: The pathology files of a regional hospital in southern Taiwan for 1989-1998 were searched for malignant lymphoma, lymphoproliferative disorder, and Hodgkin disease (HD). The results of light microscopy, immunohistochemistry, and in situ hybridization for Epstein-Barr virus-encoded RNA (EBER) were correlated with clinical findings, and all cases were classified according to REAL. RESULTS: A total of 205 cases were analyzed retrospectively. There were 197 cases (96.1%) of non-Hodgkin lymphoma (NHL) and 8 cases (3. 9%) of HD. Among the 197 NHL cases, 161 (81.7%) were of B-cell lineage and 36 (18.3%) were of T-/natural killer cell lineage. Diffuse large B-cell lymphoma, extranodal marginal zone lymphoma, and follicular lymphoma were the most common B-cell subtypes and represented 47.2%, 19.3%, and 6.1%, respectively, of all NHL cases. Among the 36 cases of T-/natural killer cell lineage, unspecified peripheral T-cell lymphoma (8.6%), T-/natural killer cell lymphoma (angiocentric lymphoma) (4.1%), and anaplastic large cell lymphoma (3.6%) were the most common subtypes. Seven of eight T-/natural killer cell lymphoma cases were positive for EBER. The eight cases of HD were classified as lymphocyte-rich classic (two cases), nodular sclerosis (two cases), and mixed cellularity (four cases) subtypes. Three of these eight cases were positive for EBER. CONCLUSIONS: To the authors' knowledge this study is the first in Taiwan using the REAL classification and it again confirms the different geographic distribution of the various subtypes of malignant lymphoma. The frequency of T-/natural killer cell lineage NHL in Taiwan is higher than that in Western countries but not as high as reported previously.