Endotoxin is a cell wall component from Gram-negative bacteria, and inhaled endotoxin contributes significantly to the induction of airway inflammation and dysfunction. Background levels of endotoxin have not yet been extensively described. In this study, airborne endotoxin was measured with a standardized protocol in 5 types of background environment (169 samples) in Denmark from October to May. Endotoxin levels in a greenhouse (median = 13.2 EU/m3) were significantly higher than in the other environments. The air from biofuel plants (median = 5.3 EU/m3), the air on congested streets (median = 4.4 EU/m3) and on an agricultural field (median = 2.9 EU/m3) had higher endotoxin contents than the air in industrial areas (median = 1.3 EU/m3) or in towns (median = 0.33 EU/m3). Levels in industrial areas were significantly higher than in towns. A literature study revealed background levels of endotoxin on different continents between 0.063-410 EU/m3, with median or mean values between 0.063-3.6 EU/m3. Endotoxin concentrations in towns and industrial areas were higher in April and May than in autumn and winter, and were higher in October than in winter. These data of exposure in background environments and of seasonal variation are helpful for public health practitioners, epidemiologists and industrial hygienists.
To determine the influence of endotoxin on the incidence of acute respiratory illness during the first 2 years of life, we carried out a longitudinal follow-up study, beginning at birth, of 332 children born in Prince Edward Island, Canada. We measured 5-day averaged air endotoxin in the homes of children, whose parents provided information by daily symptom diaries and twice-monthly telephone contact for up to 2 years. Endotoxin concentration was 0.49 +/- 3.49 EU/m3 (geometric mean +/- geometric SD), and number of annualized illness episodes was 6.83 +/- 2.80 (mean +/- SD). A doubling of the air endotoxin concentration was associated with an increase of 0.32 illness episodes per year (p = 0.0003), adjusted for age, year of study, breast-feeding, environmental tobacco smoke, child care attendance, indoor temperature, and income. Indoor mold surface area and fungal ergosterol were not significantly associated with endotoxin. Airborne endotoxin appears to be a risk factor for clinically symptomatic respiratory illnesses during the first 2 years of life independent of indoor fungus.
Farmers are known to be at high risk from the development of occupational airway disease. The first stage of the European farmers' study has shown that pig farmers in Denmark and Germany, poultry farmers in Switzerland and greenhouse workers in Spain were at highest risk for work-related respiratory symptoms. Therefore, the aim of this study was to determine exposure levels at relevant farm workplaces. Dust and endotoxin levels as well as microbiological concentrations were determined in 213 crop and animal farming environments by personal sampling. The highest total dust concentrations were found in poultry houses in Switzerland with median concentrations of 7.01 mg/m(3). The median airborne endotoxin concentrations in total dust ranged between 0.36 ng/m(3) in Spanish greenhouses and 257.58 ng/m(3) in poultry houses in Switzerland. Likewise, the highest median concentrations of total (2.0 x (7) cells/m(3)) and active fungi (4.4 x (5) cfu/m(3)) have been found in Swiss poultry houses. The predominant fungus taxa discovered in poultry houses were Eurotium spp. and thermophilic fungi. Cladosporium and Botrytis were mainly detected in greenhouses. The exposure level found in this study might put the farmers at risk from respiratory diseases.
Allergy to indoor allergens can cause frequent and severe health problems in children. Because little is known about the content of allergens in the indoor environments in Norway, we wanted to assess the levels of cat, dog and mite allergens in schools and day-care centers in Oslo. Allergen levels in dust samples from 155 classrooms and 81 day-care units were measured using commercially available enzyme-linked immunosorbent assay (ELISA) kits. Additionally, we measured the levels of endotoxin in 31 day-care units, using the limulus amebocyte lysate test. Most of the dust samples contained detectable amounts of cat and dog allergens. In mattress and floor dust (day-care centers), and curtain and floor dust (schools) the median Fel d 1 levels were 0.17, 0.002, 0.02 and 0.079 microg/m2, while the median Can f 1 levels were 1.7, 0.03, 0.1 and 0.69 microg/m2, respectively. Levels of cat and dog allergens in school floor dust were associated with the number of pupils with animals at home. In contrast,
This study measured and analyzed the outdoor airborne endotoxin concentration, on particulate matter (PM²·5 and PM¹°), for two cities in the interior of British Columbia, Canada. Samples were collected throughout one seasonal cycle, from October 2005 to September 2006. It was found that concentrations were generally highest in the summer and fall, and lowest in the winter and spring. Temperature and relative humidity were found to be most influential, with highest endotoxin concentrations recorded during warm periods and moderate relative humidity (35 to 75 percent). No clear association of concentration with wind direction was observed. Results were comparable between the two cities considered in this study, and concentrations were similar to or slightly higher than those reported by other studies considering urban locations. Endotoxin concentration was also found to be positively associated with agricultural dust sources identified by a source apportionment study conducted at one of the sampling locations.
Blood serum content was studied of specific antistaphylococcal antibodies (staphylolysins) in 576 donors immunized with staphylococcal anatoxin with the purpose of obtaining an antistaphylococcal plasma and antistaphylococcal immunoglobulin to be used in clinical settings. 292 donors had been immunized and examined prior to 1986, 284--after 1986 (before 1994). Comparison of the immune responses in the above periods of time permitted finding out that 13.03% of immunized donors responded to the antigenic stimulus by such paradoxical reaction as disappearance of specific antibodies; the number of persons-active respondents has gotten reduced from 17.12% to 5.98% as has the number of individuals having the baseline level of staphylolysins (1-2 ME/ml). The changes were at their greatest in donors with group A (II) blood.
The purpose of this study was to quantify and identify the airborne contamination in eastern Canadian sawmills. Seventeen sawmills were chosen to cover a wide range of size, geographic distribution, and wood species processed. Within each sawmill different work sites (debarking, sawing, sorting, or planing) were studied separately. Area sampling was performed for exposure assessment. Microbial contaminants were assessed with all-glass impingers 30 and six-stage Andersen microbial samplers; appropriate selective media and culture conditions for bacteria, thermophilic actinomycetes, molds, and yeasts were used. Inhalable dust, endotoxins, temperature, and humidity also were measured. Penicillium species were the most predominant molds with up to 40 different Penicillium species identified. Debarking was the working site most highly contaminated by molds, bacteria, and endotoxins (p=0.0001). At this working site mold levels reached a maximum of 1.5 x 10(6) CFU/m3, whereas the median values for culturable bacteria and endotoxin were 21,620 CFU/m3 and 1,081 endotoxin units/m3, respectively. Planing sites were the most highly dust contaminated (median: 3.0 mg/m3) (p
Knowledge of the effects of domestic endotoxin on children's lung function is limited. The association between domestic endotoxin and asthma or wheeze and lung function among school-age children (six to 18 years of age) was examined. The interaction between endotoxin and other personal and environmental characteristics and lung function was also assessed.
A case-control study was conducted in and around the rural community of Humboldt, Saskatchewan, between 2005 and 2007. Parents of cases reported either doctor-diagnosed asthma or wheeze in the previous year. Controls were randomly selected from those not reporting these conditions. Data were collected by questionnaire to ascertain symptoms and conditions, while spirometry was used to measure lung function including forced vital capacity and forced expiratory volume in 1 s. Dust collected from the child's play area floor and the child's mattress was used to quantify endotoxin, and saliva was collected to quantify cotinine levels and assess tobacco smoke exposure.
There were 102 cases and 207 controls included in the present study. Lower forced expiratory volume in 1 s was associated with higher mattress endotoxin load among female cases (beta=-0.25, SE=0.07 [P
Cites: Am J Respir Cell Mol Biol. 2000 May;22(5):604-1210783133
Premature birth causes significant health risks of the neonate and increases the cost for neonatal care. Urogenital infection, often caused by Gram-negative bacteria, is a known risk factor. Toll-like receptor-4 (TLR4) is the major endotoxin-signaling receptor and as such is crucial for the initiation of the innate immune response against Gram-negative bacteria. Recently, a variant in the human TLR4 gene was shown to be associated with impaired receptor function and an increased likelihood of Gram-negative sepsis. In the present study, we determined whether the same polymorphism in TLR4 gene is associated with an increased risk for premature birth. We analyzed genotypes for a Finnish study population consisting of a total of 351 term infants and 440 premature infants (gestational age