The relation between modeled odor exposure from livestock farming and odor annoyance among neighboring residents.

PURPOSE: Odor annoyance is an important environmental stressor for neighboring residents of livestock farms and may affect their quality of life and health. However, little is known about the relation between odor exposure due to livestock farming and odor annoyance. Even more, the relation between odor exposure and odor annoyance is rather complicated due to variable responses among individuals to comparable exposure levels and a large number of factors (such as age, gender, education) that may affect the relation. In this study, we (1) investigated the relation between modeled odor exposure and odor annoyance; (2) investigated whether other factors can affect this relation; and (3) compared our dose-response relation to a dose-response relation established in a previous study carried out in the Netherlands, more than 10 years ago, in order to investigate changes in odor perception and appreciation over time. METHODS: We used data from 582 respondents who participated in a questionnaire survey among neighboring residents of livestock farms in the south of the Netherlands. Odor annoyance was established by two close-ended questions in a questionnaire; odor exposure was estimated using the Stacks dispersion model. RESULTS: The results of our study indicate a statistically significant and positive relation between modeled odor exposure and reported odor annoyance from livestock farming (OR 1.92; 95 % CI 1.53-2.41). Furthermore, age, asthma, education and perceived air pollution in the environment are all related to odor annoyance, although they hardly affect the relation between estimated livestock odor exposure and reported odor annoyance. We also found relatively more odor annoyance reported among neighboring residents than in a previous study conducted in the Netherlands. CONCLUSIONS: We found a strong relation between modeled odor exposure and odor annoyance. However, due to some uncertainties and small number of studies on this topic, further research and replication of results is recommended.

Comparing the effectiveness of interventions to improve ventilation behavior in primary schools.

UNLABELLED: Poor air quality in schools has been associated with adverse health effects. Indoor air quality can be improved by increasing ventilation. The objective of this study was to compare the effectiveness of different interventions to improve ventilation behavior in primary schools. We used indoor CO(2) concentrations as an indicator. In 81 classes of 20 Dutch primary schools, we applied three different interventions: (i) a class-specific ventilation advice; (ii) the advice combined with a CO(2) warning device and (iii) the advice combined with a teaching package. The effectiveness of the interventions was tested directly after intervention and 6 weeks after intervention by measuring the CO(2) concentrations and comparison with a control group (iv). Before intervention, the CO(2) concentration exceeded 1000 ppm for 64% of the school day. The class-specific ventilation advice without further support appeared an ineffective tool to improve ventilation behavior. The advice in combination with a CO(2) warning device or the teaching package proved effective tools and resulted in lower indoor CO(2) concentrations when compared with the control group. Ventilation was significantly improved, but CO(2) concentrations still exceeded 1000 ppm for more than 40% of the school day. Hence, until ventilation facilities are upgraded, the CO(2) warning device and the teaching package are useful low-cost tools. PRACTICAL IMPLICATIONS: To improve ventilation behavior and indoor air quality in schools, CO(2) warning device and teaching package combined with a class-specific ventilation advice, are effective tools, while giving the ventilation advice solely, is not effective. Although ventilation is significantly improved through behavioral change, the ventilation rate is still insufficient to maintain good air quality during the full school day. Therefore, the improvement of the ventilation facilities is recommended. Hence, until ventilation facilities in schools are upgraded, the CO(2) warning device and the teaching package are useful low-cost tools to improve current indoor air quality.

Time-resolved fluoroimmunoassay for unconjugated estrogen in urine: comparison with a fluorometric assay for total estrogen and application in an in vitro fertilization program.

A time-resolved fluoroimmunoassay (TR-FIA) for unconjugated estrogens in human urine is described. 6-Keto-17 beta-estradiol-6-(O-carboxymethyl)oxime:bovine serum albumin is immobilized onto microtiter strip wells and the coated wells are incubated with 17 beta-estradiol standard preparations or unknowns with a polyclonal antiserum to 17 beta-estradiol-16,17-monosuccinyl:albumin. The antiserum-bound estrogen is detected by incubation with a europium-labeled anti-rabbit IgG that serves as both second antibody and tracer. After the immunoreactions, the bound portion of the labeled antiserum is quantified by dissociating the Eu3+ in a fluorescence-enhancement solution and measuring its fluorescence with a time-resolved fluorometer. The detection limit of the TR-FIA is 24 pmol of 17 beta-estradiol per liter; the analytical range extends to 1.8 nmol/L. This assay is a convenient alternative to radioimmunoassay and to the automated Kober-Ittrich fluorometry of total estrogen. Its advantages include short counting times; use of nonradioactive, stable reagents, all of which are commercially available; and more nearly complete automation. We conclude that this TR-FIA, compared with the Kober-Ittrich fluorometric assay (J Endocrinol 1957; 16:49-56), provides the clinician with equivalent information during follicular development therapy as part of an in vitro fertilization program.

Bacteriologic epidemiology of Hemophilus influenzae type b strains causing invasive infections in Finland.

Consecutive Hemophilus influenzae type b (Hib) isolates (333 total) from children with invasive disease in Finland in 1985-1986 were analyzed. All belonged to the common genetic clusters described in the USA and Europe. However, detailed typing demonstrated some characteristics unique to Hib strains in Finland. Of the isolates, 86% belonged to one of four distinct patterns according to the combination of outer membrane protein subtype, biotype, and lipopolysaccharide serotype: 1-I-1 (25%), 1-II-9 (8%), and 1c-I-1 (18%). Pattern 1-II-9 has not been previously reported; it was most commonly found in the most densely populated area of Finland and among children cared for outside the home. Multilocus enzyme electrophoresis revealed that 87% of isolates with the pattern 1c-I-1 belonged to the electrophoretic type 21.8, which is seldom recovered from patients with invasive Hib disease in other countries.

Comparison of two nonculture techniques for detection of Hemophilus influenzae in sputum. In situ hybridization and immunoperoxidase staining with monoclonal antibodies.

Two nonculture methods, in situ hybridization and immunoperoxidase staining with monoclonal antibodies, were compared for the detection of Hemophilus influenzae in 184 sputa. For in situ hybridization, a biotin-labeled probe of total genomic DNA of H influenzae type b was prepared that hybridizes specifically with H influenzae, H parainfluenzae, H hemolyticus, and H parahemolyticus DNA. Immunoperoxidase staining was done with monoclonal antibody 8BD9 directed against outer membrane protein P6 of H influenzae. Both techniques detected Hemophilus in sputum equally well and were superior to culture: all 30 sputum samples culture-positive for H influenzae were positive on both nonculture tests, and 13 additional positive sputum samples were detected from which Hemophilus was not cultured. The higher sensitivity of the nonculture tests was mainly attributed to culture failure because of overgrowth of H influenzae by other bacteria, especially in patients with cystic fibrosis. The immunoperoxidase staining technique appeared slightly easier and quicker to perform than the in situ hybridization test. For the in situ DNA hybridization probe, DNA can be prepared from any strain of H influenzae. The immunoperoxidase test requires monoclonal antibody 8BD9 but has a higher specificity than the hybridization technique. Both techniques can be reliably applied, especially for the detection of Hemophilus in sputum of patients with cystic fibrosis.

Comparison of antibiotic resistant and sensitive strains of Haemophilus influenzae type b in The Netherlands by outer-membrane protein subtyping.

The percentage of beta-lactamase producing Haemophilus influenzae strains from patients with meningitis in The Netherlands increased from 0% in 1975/1976 to 4.6% in 1985/1986 (n = 1559). Twenty-three isolates resistant to ampicillin, penicillin, chloramphenicol, rifampicin and/or tetracycline were subtyped to determine if one resistant strain was spreading. (Sub)typing was performed by capsular typing, analysis of the major outer membrane protein patterns on sodium dodecylsulfate gels (SDS-PAGE subtypes), lipopolysaccharide serotyping and biotyping. The (sub)types of the resistant strains were similar to those of sensitive strains, thus indicating that antibiotic resistant strains develop at random.

Preparation of cell envelopes of large numbers of individual bacterial strains with the use of an automatic cell disruptor.

Analysis of the cell envelopes of large numbers of bacterial strains is used for the epidemiological and taxonomic investigation of clinical, veterinarian, and ecological isolates. Isolation of cell envelopes requires lysis of the bacteria. We developed an apparatus to disrupt bacterial cells of 200 different isolates in suspension by ultrasonication automatically. It is composed of modified standard laboratory equipment (fraction collector, cooling unit, pump), a standard ultrasonifier, and a newly designed control unit, which includes a sampler. This apparatus was applied to the analysis of cell envelope proteins of 96 Haemophilus influenzae strains on sodium dodecyl sulfate-polyacrylamide gel electrophoresis within 3 days after the first culture.

The erythrocyte and epithelial cell receptors for Haemophilus influenzae are expressed independently.

The Anton blood group antigen has been shown to be the erythrocyte receptor for Haemophilus influenzae. Cord erythrocytes, which lack the Anton antigen, were not agglutinated by H. influenzae (L. van Alphen, J. Poole, and M. Overbecke, FEMS Microbiol. Lett. 37:69-71, 1986). Twenty-eight erythrocyte suspensions from newborns less than 4 days old were also not agglutinated, but 23 of 56 erythrocyte suspensions from 4- to 50-day-old newborns and 23 of 35 erythrocyte suspensions from older infants were agglutinated. Positive hemagglutination correlated with the presence of the Anton antigen on the erythrocytes for 163 of 173 (P less than 0.0001). Adherence of H. influenzae to buccal epithelial cells obtained from six newborns within 3 days after birth was as strong as that found with adult epithelial cells, whereas the erythrocytes from five of six of these newborns were not agglutinated by the bacteria. Adherence of H. influenzae to epithelial cells of 15 donors was not inhibited by anti-Anton serum. Moreover, H. influenzae carrying fimbriae adhered to epithelial cells of an Anton-negative donor. From these results we conclude that the age at which the erythrocyte receptor for H. influenzae is expressed is the same as for the Anton antigen, but that the receptor on the epithelial cells is already expressed at birth and is not identical to the Anton antigen.