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71.
BACKGROUND: The purpose was to study the test-retest reliability and internal consistency of questions in a questionnaire concerning working conditions and health and the inter-rater reliability of observations and measurements according to an ergonomic checklist. METHOD: Fifty-seven operators participated in a retest questionnaire and 58 operators participated in an inter-observer test. RESULTS: The questions had fair to good or higher reliability in 142 of the total of 312. Twenty-seven of the total of 44 variables in the ergonomic checklist were classified as having fair to good or higher reliability. CONCLUSIONS: About half of the questions had fair to good or higher reliability and can be recommended for further analyses. The majority of variables in the ergonomic checklist were classified as having fair to good or higher reliability. Low reliability does not necessarily indicate that the reliability of the test, per se, is low but may signify that the conditions measured vary over time or that the answers are aggregated in one part of the scale.  相似文献   
72.
Decomposition studies were carried out at sites throughout Sweden, including the four Integrated Monitoring sites. Scots pine needle litterbag weight loss measurements over 3 or 5 years were determined at 26 sites and repeated up to 27 times, depending on the site. Humus layer respiration rates were determined for 20 sites in 1987–1989 and repeated in 2007–2008. Partial Least Squares (PLS) regression was used to elucidate the relative importance of climatic and soil factors. Annual needle weight losses decreased only slowly (20–10%) over 3–5 years for all northern (>60°N) sites but decreased sharply from 30 to 10% in the third year in southern (<60°N) sites. Respiration rates of southern sites were less (40% on average) than those of northern sites. Humus layer N was positively correlated to needle weight loss during the first and the second years, but negatively correlated in the third year and to respiration rates. The results indicated that litter formed in southern Sweden became more recalcitrant in later stages of decomposition compared to litter produced in northern Sweden.  相似文献   
73.
We studied the bioaccumulation of lead in selected tissues of Prussian carp Carassius gibelio (Bloch, 1782) during 12 and 24 months exposure to different doses of this metal in feed and the elimination of lead from tissues during the following 12-month depuration period. Lead concentration was determined using atomic absorption spectrometry method. The highest lead concentrations were observed at 2.0?±?0.54 to 7.4?±?1.1 mg?kg?1 in the kidney, 3.0?±?0.13 to 5.2?±?0.17 mg?kg?1 in the bone, and 4.5 (±0.4)?mg?kg?1 in the hepatopancreas of fish from groups exposed to lead dietary concentration from 8 to 49 mg?kg?1 for 24 months. The rate of accumulation were generally the highest at the beginning of exposure as evidenced by the highest monthly increments of bioaccumulation observed after 3 months of contamination for muscles, hepatopancreatic gland, intestine, and gills. Also analysis of the monthly increments of lead bioaccumulation in bone tissue and the highly significant coefficients of correlation indicate that the dynamics of accumulation are clearly dependent on dose of exposure. Depuration of accumulated lead from the organs depended mainly on tissue and duration of elimination period. Very rapid depuration was observed in soft tissues such as the intestine or muscles. Very low elimination was observed for scales and bones where until the end of the experiment highly significant lead concentration differences were observed in all groups in relation to the control group. Chronic dietary exposure in the range of 8–49 mg Pb?kg?1 resulted in no significant effects on the growth and survival of Prussian carp females.  相似文献   
74.
Instantaneous (discrete) and time-integrated (composed) samples were collected during a 19-week period in a watershed impacted by discontinuous discharges from local tanneries (Carpathians Mountains, Poland). Existence of the impoundment reservoir in this watershed allowed investigation of its role in chromium transport. In collected samples, dissolved and particulate chromium concentrations were measured to apportion both loads. This study has demonstrated that the impoundment reservoir retains not only particulate but also a dissolved form of chromium and its efficiency reaches 74–94 %. Sampling results proved that chromium contamination in the investigated river is variable and discontinuous. Discrete sampling can lead to an underestimation of chromium contamination level (up to 78 %), especially when illegal/unexpected discharges occur in the watershed. A discrete sampling regime also produces less reliable data for contaminant budget calculations, especially in sites where strong variability of contamination is anticipated, while at the output from reservoirs, the load can be reasonably estimated using this mode of sampling.  相似文献   
75.
ABSTRACT

The aim of this study is to assess the disappearance of boscalid (IUPAC name: 2-chloro-N-[2-(4-chlorophenyl)phenyl]pyridine-3-carboxamide) and pyraclostrobin (IUPAC name: methyl N-[2-[[1-(4-chlorophenyl)pyrazol-3-yl]oxymethyl]phenyl]-N-methoxycarbamate) residues in apple fruit, and to verify whether an organic fertilizer enriched with strains of antagonistic microorganisms can reduce pesticide residue levels. Field trials were conducted in a commercial orchard on apples of the Gloster variety, during 21 days after the treatment with Bellis 38 WG and the subsequent application of Zumba Plant formulation containing Bacillus spp., Trichoderma spp. and Glomus spp. In control samples, the decrease rate of boscalid and pyraclostrobin residue levels followed an exponential function, described by formulae Rt = 0.2824e?0.071t and Rt = 0.1176e?0.060t, with the coefficient of determination of r2 = 0.8692 and r2 = 0.9268, respectively. These levels dropped to half (t1/2) of their initial values after 9.8 and 11.5 days, respectively. The treatment with Zumba Plant resulted in a reduction in boscalid and pyraclostrobin residue levels by 52% and 41%, respectively. The results of this study are of importance for horticulture sciences and for producers of apples using plant protection products (PPPs).  相似文献   
76.
Air pollutants emitted while processing phenol-formaldehyde resins have been investigated. Gas chromatography-mass-selective detection was used to separate and identify chemical compounds. It was determined that workers were exposed to formaldehyde in all workplaces. Besides, phenol, acetaldehyde, acrylaldehyde, 2-furaldehyde, xylene, ethylbenzene, toluene, tetrachlorethene, ethyl acetate, butyl acetate were found during the production of frictional materials; and 2-furaldehyde, phenol, naphthalene, 2-furan-methanol, polycyclic aromatic hydrocarbons (PAHs) during the production of abrasive materials. Quantitative analyses were performed with gas chromatogra-phy and high performance liquid chromatography. Assessment of occupational exposure indicated that chemical compounds emitted during the investigated processes might be dangerous for human health, mainly because of suspected carcinogenic compounds: formaldehyde and PAHs.  相似文献   
77.
The musculoskeletal health among 57 operators at 1 call centre in Sweden was studied with 10 monthly follow-ups, parallel to a reference group of 1,226 professional computer users in other occupations. Operators at this call centre were more symptom-loaded than the other professional computer users in spite of their younger age and shorter exposure to computer work. Symptoms were long-lasting or recurrent. Muscle tenderness and nerve affections in the neck- shoulder region were the most common specific findings and diagnoses at medical examination of incident symptom cases. More extensive studies should be done on the working conditions and health status among call centre workers.  相似文献   
78.
Interests in the determination of different arsenic species in natural waters is caused by the fact that toxic effects of arsenic are connected with its chemical forms and oxidation states. In determinations of water samples inorganic arsenate (As(III), As(V)), methylated metabolities (MMAA, DMAA) and other organic forms such as AsB, AsC, arsenosugars or arsenic containing lipids have the most importance. This article provides information about occurrence of the dominant arsenic forms in various water environments. The main factors controlling arsenic speciation in water are described. The quantification of species is difficult because the concentrations of different forms in water samples are relatively lowcompared to the detection limits of the available analytical techniques. Several hyphenated methods used in arsenic speciation analysis are described. Specific advantages and disadvantages of methods can define their application for a particular sample analysis. Insufficient selectivity and sensitivity of arsenic speciation methods cause searching for a new or modifications already existing techniques. Some aspects of improvement and modifications of the methods are highlighted.  相似文献   
79.
A considerable area of soils with low abundance of plant-available phosphorus and relatively low consumption of phosphorus fertilisers recorded in Poland over the last 20–25 years suggests that the dispersion of phosphates from arable soils in Poland can be low. The literature, however, provides reports on a considerable share of Polish agriculture in phosphorus pollution of Baltic Sea waters. The literature provides no data concerning phosphorus sorption parameters of arable soils in Poland. Due to this, the study involved the analysis of sorption properties: 1-point phosphorus sorption index (PSI) and degree of phosphorus saturation, based on molar ratio P, Al, and Fe determined by the Mehlich-3 method (DPS-1M3?=?P / (Al?+?Fe) and DPS-2M3?=?P / Al), 59 soils representing the main types of texture of soils in Poland, characterised by variable content of plant-available phosphorus by Egner-Riehm DL, organic carbon, and soil pH. The obtained results suggest that the soil texture has a lower effect on sorption properties (PSI) than the degree of acidification. Sorption parameters of soils increased with soil acidification as a result of an increase in the content of Al and Fe extracted by the Mehlich-3 extract in strongly acidified soils. An important finding of our study was evidencing that within the same class of abundance in plant-available phosphorus, the soils varied in the degree of phosphorus saturation and content of active phosphorus. This suggests the possibility of losses of phosphorus even from soils with low abundance of the component provided they are characterised by a high value of parameters DPS-1M3 and DPS-2M3.  相似文献   
80.
BACKGROUND: Animal and epidemiologic data indicate that exposure to persistent organochlorine pollutants (POPs) may disrupt the hypothalamus-pituitary-thyroid (HPT) and the hypothalamus-pituitary-gonadal (HPG) axes. We have assessed whether the POP-biomarkers 2,2'4,4',5,5'-hexachlorobiphenyl (CB-153) and 1,1-dichloro-2,2-bis(4-chlorophenyl)-ethene (p,p'-DDE) affect thyrotropin (TSH), thyroid hormones, gonadotropins or sex hormone concentrations in men. METHODS: Lipid adjusted serum concentrations of CB-153, and p,p'-DDE, were determined in 196 men (median age 59 years, range 48-82). Hormone analyses in serum were performed with immunoassays. The effect of CB-153 and p,p'-DDE (as continuous or categorized variables) were evaluated by linear regression models, adjusting for potential confounders. RESULTS: There was a significant positive association between p,p'-DDE and TSH. An increase of 100 ng/g lipid of p,p'-DDE corresponded to an increase of 0.03 mU/l (95% Confidence Interval (CI) 0.01, 0.05) in TSH level. The explanatory value (R(2)) of the multivariate model was only 7%. Moreover, there was a significant negative association between p,p'-DDE and estradiol. An increase of 100 ng/g lipid of p,p'-DDE corresponded to a decrease of 0.57 pmol/l (95% CI -1.0, -0.12) in estradiol level. The R(2)-value was only 4%. No associations were observed between any of the POP biomarkers and the other hormones. CONCLUSIONS: The positive association between p,p'-DDE and TSH and the negative association between p,p'-DDE and estradiol, among middle-aged and elderly men, were not accompanied by associations between the POP-markers and thyroxin, testosterone, and gonadotropins, respectively. The results gives some additional support for that POP exposure may affect HPT- and HPG-axes also in humans, but the overall epidemiological data are still not coherent enough to allow any firm conclusions.  相似文献   
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