Epidemiology of allergic rhinitis in Quebec: from a 2008 population-based survey.

INTRODUCTION: Our objective was to estimate the prevalence of symptoms and the proportion of a lifetime physician-based diagnosis of allergic rhinitis (AR) in the province of Quebec among people aged 15 years and older. METHODS: The 2008 Quebec Population Health Survey provided data on the prevalence of symptoms and proportion of lifetime physician-based diagnoses of AR. The prevalence of symptoms was defined as the proportion of individuals who, in the absence of a cold or the flu, had nasal and ocular symptoms in the 12 months before the survey. RESULTS: The reported prevalence of AR symptoms was 17%, although 9% did not have a diagnosed condition. Reported prevalence was lowest in those aged 65 years and older (12%) and was more common among women (19%) than men (15%). The estimated prevalence of lifetime physician-based diagnosis was 17%. CONCLUSION: AR prevalence is high in Quebec with about 1 in 6 people experiencing symptoms. The condition is underdiagnosed and might also be undertreated.

TITRE: Épidémiologie de la rhinite allergique au Québec d'après une enquête populationnelle de 2008. INTRODUCTION: Notre étude avait pour objectif d'estimer la prévalence des symptômes et du diagnostic médical de la rhinite allergique (RA) chez les personnes âgées de 15 ans et plus au Québec. MÉTHODOLOGIE: L'Enquête québécoise sur la santé de la population de 2008 a fourni les données de la prévalence des symptômes de RA et de la proportion de RA diagnostiquée par un médecin au cours de la vie. La prévalence des symptômes a été définie comme la proportion d'individus qui, en l'absence de rhume ou de grippe, ont eu des symptômes nasaux et oculaires au cours des 12 mois précédant l'enquête. RÉSULTATS: La prévalence des symptômes de RA a été estimée à 17 %, dont 9 % de personnes n'ayant pas reçu de diagnostic. La RA était moins fréquente chez les répondants de 65 ans et plus (12 %) et elle était plus répandue chez les femmes (19 %) que chez les hommes (15 %). La proportion de RA diagnostiquée par un médecin au cours de la vie a été estimée à 17 %. CONCLUSION: La RA est fréquente au Québec. En effet, environ une personne sur six en éprouve les symptômes. Cette maladie est sous-diagnostiquée et sans doute aussi sous-traitée.

Association between indicators of livestock farming intensity and hospitalization rate for acute gastroenteritis.

To evaluate associations between indicators of livestock farming intensity (manure surplus and livestock density) and acute gastroenteritis hospitalization (AGH) rate, we conducted an ecological study on 306 selected agricultural municipalities of Quebec. We estimated the AGH rate for the period 2000-2004 from the Quebec hospital database. Multivariate Poisson regression was used to estimate the strength of association between the farming indicators and AGH with adjustment for confounders. The modifying effect of age and water source was also evaluated. Association between manure and AGH was observed in children, especially those aged 0-4 years for selected zoonotic infections [adjusted hospitalization rate ratio (aHRR) 1.93, 95% CI 1.21-3.09]. The risk ratio was higher for subjects using ground-water source. An increasing HRR trend with each additional level of poultry density was observed in children aged 0-4 years, especially for Salmonella infections. We conclude that livestock farming intensity may be linked to bacterial acute gastroenteritis in children.

Effects of dibromoacetonitrile on rats following 13-week drinking water exposure.

The subchronic toxicity of dibromoacetonitrile (DBAN), a disinfection by-product in drinking water, was studied in the rat. Male (180+/-18 g) and female (152+/-9 g) Sprague-Dawley rats (10 animals per group) were fed DBAN in organic-free distilled water at concentrations of 0.1, 1, 10 and 100 ppm for 13 weeks. Control rats received organic-free distilled water only. Water intakes in the highest dose males and females were reduced by 25 and 32% as compared to the controls, respectively (P<0.05), with no significant reductions in food consumption and body weight gain. The organ to body weight ratio was significantly increased in the highest-dose males and females for kidneys but not for the brain, liver, spleen, thymus and testicles. In the males, decreases were detected in serum uric acid levels at 1 and 100 ppm, and in urinary uric acid at 10 and 100 ppm. Decreased serum protein was detected in the highest-dose males and decreased serum LDH was found in the highest-dose females. Both the white blood cell and lymphocyte counts were significantly elevated in the highest-dose females. A significant increase in hepatic catalase activity was observed only in males starting at 1 ppm, and increased palmitoyl-CoA oxidase (PCO) activity was found in males and females of the highest dose group. In the males, decreased thiobarbituric acid reactive substance (TBARS) level was detected in the liver at 1.0 and 100 ppm groups, while increased TBARS was found in the serum at 100 ppm DBAN. No treatment-related changes were detected in the activities of hepatic benzyloxyresorufin O-dealkylase (BROD), pentoxyresorufin O-dealkylase (PROD) and ethoxresorufin O-deethylase (EROD), and in hepatic UDP-glucuronosyltransferase (UDPGT) and glutathione S-transferases (GST). Although DBAN is a potent inhibitor of hepatic aldehyde dehydrogenase (ALDH) and GST in vitro, there was no evidence of suppression of these enzymes in the treated animals. Mild histological changes were detected in animals receiving the highest dose, consisting of collapsed angularity, increased epithelial height in the thyroid of both sexes, and cytoplasmic vacuolation and nuclear vesiculation in the thyroid of females, increased myeloid to erythroid ratio in the bone marrow of both sexes, and cytoplasmic inclusions in the proximal tubules of male kidneys. In summary, treatment effects occurred predominantly at 100 ppm and included in both sexes: increased kidney weights, histological changes in the thyroid and bone marrow, and increased peroxisomal enzyme activities; and in males: decreased serum and urinary uric acid levels, and indication of oxidative stress. The no-observed-adverse-effect level (NOAEL) was therefore judged to be 10 ppm, equivalent to 1.11 and 1.21 mg/kg/day in the males and females, respectively.

Exposure of the Inuit population of Nunavik (Arctic Quebec) to lead and mercury.

The authors conducted a survey during 1992 to evaluate blood levels of lead and mercury in Inuit adults of Nunavik (Arctic Quebec, Canada). Blood samples obtained from 492 participants (209 males and 283 females; mean age = 35 yr) were analyzed for lead and total mercury; mean (geometric) concentrations were 0.42 micromol/l (range = 0.04-2.28 micromol/l) and 79.6 nmol/l (range = 4-560 nmol/l), respectively. Concentrations of omega-3 fatty acid in plasma phospholipids--a biomarker of marine food consumption--were correlated with mercury (r = .56, p < .001) and, to a lesser extent, with blood lead levels (r = .31, p < .001). Analyses of variance further revealed that smoking, age, and consumption of waterfowl were associated with lead concentrations (r2 = .30, p < .001), whereas age and consumption of seal and beluga whale were related to total mercury levels (r2 = .30, p < .001). A significant proportion of reproductive-age women had lead and mercury concentrations that exceeded those that have been reportedly associated with subtle neurodevelopmental deficits in other populations.

Organochlorine exposure and the risk of endometriosis.

OBJECTIVE: To compare mean concentrations of organochlorine in women with a new diagnosis of endometriosis and in controls. DESIGN: Case-control study. SETTING: Women attending an institutional clinic of reproductive endocrinology. PATIENT(S): Cases and controls were selected among women who underwent laparoscopy for chronic pelvic pain, infertility, or tubal fulguration between January 1994 and December 1994. Eighty-six women with endometriosis and 70 controls, matched for the indication for laparoscopy, were recruited. MAIN OUTCOME MEASURE(S): Mean organochlorine plasma concentrations of 14 polychlorinated biphenyl congeners and 11 chlorinated pesticides were compared between the cases and controls. Analysis of covariance was used to adjust means for confounding variables, and odds ratios were estimated by logistic regression. RESULT(S): Crude geometric mean concentrations did not differ significantly between cases and controls for any of the organochlorine compounds. Similarly, crude or adjusted means of the sum of polychlorinated biphenyl congeners, the sum of chlordanes, or the sum of dichlorodiphenyltrichloroethanes did not differ between the groups. There was no significant linear trend in the adjusted odds ratios for endometriosis as organochlorine concentrations increased. CONCLUSION(S): These results suggest that exposure to polychlorinated biphenyls and chlorinated pesticides during adulthood is not associated with endometriosis in the general population.

PCBs and dioxin-like compounds in plasma of adult Inuit living in Nunavik (Arctic Quebec).

Inuit people residing in the Arctic are unusually exposed to organochlorines through their traditional diet which includes large quantities of sea mammal fat. Recently, 499 Inuit adults from Nunavik (Arctic Quebec) participated in a large health survey and donated a blood sample for organochlorine and heavy metal analysis. Twenty pooled plasma samples were formed, each made of individual samples from the same age group, sex, and region of residence, to allow for dioxin-like compound determination. The mean total concentration of PCBs and dioxin-like compounds (the latter expressed in 2,3,7,8-TCDD toxic equivalents) were respectively 4.1 mg/kg lipids and 184.2 ng/kg lipids, compared to 0.13 mg/kg lipids and 26.1 ng/kg lipids for three control pooled plasma samples from Southern Quebec. Total PCBs and dioxin-like compound concentrations were strongly correlated (r = 0.98; p < 0.0001), increased with age and were greater in men than in women. Although the body burdens of PCBs and dioxin-like compounds are close to those which induced adverse health effects in laboratory animals, dietary benefits from the sea-food based diet still outweigh the hypothetical health risks.

Organohalogen residues in human adipose autopsy samples from six Ontario municipalities.

Human adipose tissue samples obtained during autopsies in 6 Canadian Great Lakes municipalities were analyzed for chlorobenzenes, polychlorobiphenyls, and organohalogen pesticide residues. The frequency of occurrence and the range and mean for 28 organohalogen residues are reported for male and female donors in each municipality. Overall mean residue values in females were significantly higher than those in males for hexachlorobenzene, beta-HCH, p,p'-DDE,p,p'-DDD + o,p'-DDT, and p,p'-DDT. The means and ranges of residue values were similar to those reported in previous Canadian surveys.

Contribution of chlorination to the mutagenic activity of drinking water extracts in Salmonella and Chinese hamster ovary cells.

The production of chlorinated by-products through chlorine disinfection of drinking water has been well documented. Natural organic precursors for these chemicals include fulvic and humic acids, the chlorination of which leads to the production of mutagenic compounds. Comparisons of extracts of raw versus treated waters have confirmed that clorination during water treatment produces mutagenic activity in the Salmonella (Ames) test. Present work on XAD-2 extracts of raw and chlorinated water from six municipalities in the Great Lakes region of Canada has involved a battery of mutagenicity assays for various genetic endpoints: the Salmonella test, the sister-chromatid exchange (SCE), and the micronucleus (MN) induction in Chinese hamster ovary (CHO) cells. All extracts of treated (chlorinated), but none of untreated, water were mutagenic in the Salmonella assay. On the other hand, extracts of both treated and untreated water samples showed activity in the SCE and MN assays, but no consistent pattern of response with regard to treatment (chlorination) was evident. These data show that chlorination contributes mutagens to drinking water and suggest that mammalian in vitro assays may be more sensitive for detecting mutagenicity in water samples than the Salmonella test.

Determination of halogenated contaminants in human adipose tissue.

A method has been developed for determination of organochlorine contaminants in human adipose tissue. After fat extraction from the tissue with acetone-hexane (15 + 85, v/v), organochlorines were fractionated from fat by gel permeation chromatography with methylene chloride-cyclohexane (1 + 1, v/v) as solvent. After Florisil column cleanup, the GPC extract was analyzed by capillary column gas chromatography using 2 columns of different polarity. Compound identity was confirmed by gas chromatography-mass spectrometry using selected ion monitoring. Recoveries for fortification levels of 10-500 ng/g were greater than 80% except for trichlorobenzene and hexachlorobutadiene (ca 60%).

Are video display terminals a source of increased PCB concentration in the working atmosphere? One answer.

In response to the question: "Are datascreen terminals a source of increased PCB concentrations in the working atmosphere?" a study of PCB emissions from video display terminals (VDT) was undertaken. Emissions of 2.4 to 8.1 ng PCB/h were observed from VDT located in a building (1) where the mean PCB level in the air was 46 ng PCB/m3 during the test period, whereas no PCB emissions were detected from VDT located in a building (2) where no PCB could be detected in the ambient air. However, both the air and the VDT from building 2 were found to be contaminated with polycyclic aromatic hydrocarbons. We conclude that the observed PCB emissions from VDT are the result of the vapourization of PCB deposited onto the VDT from the PCB contaminated air and do not originate from the electrical components of the VDT.

A comparison of organochlorine residues in human adipose tissue autopsy samples from two Ontario municipalities.

Human adipose tissue samples obtained during autopsies in a Canadian Great Lakes community, Kingston, Ontario, and a second community, Ottawa, Ontario, were analyzed for organochlorine pesticides, polychlorobiphenyls, chlorobenzenes, and chlorophenols. Significantly different levels of Dichlorodiphenyl -dichloroethane, mirex, hexachlorobenzene, and 2,3,4,6-tetrachlorophenol were found in Kingston adipose tissues compared to Ottawa tissues. Residue levels of oxychlordane , mirex, and polychlorinated biphenyls were significantly different in Kingston males versus Kingston females. The means and ranges of residue levels were contrasted with those reported in previous Canadian surveys.

Determination of organic phosphate triesters in human adipose tissue.

A method of analysis has been developed for the determination of organic phosphate triesters in human adipose fat at low ng/g levels. After fat extraction from the tissue with benzene (or acetone-hexane, 15 + 85, v/v), phosphates were fractionated from fat by gel permeation chromatography with methylene chloride-cyclohexane (5 + 95, v/v) as solvent. After Florisil column cleanup, the GPC extract was analyzed by capillary column gas chromatography using a nitrogen-phosphorus selective detector. Recoveries at the 2.5, 10, and 25 ng/g levels were greater than 75% except for tri(2,4-xylenyl) phosphate (ca 65%). Of 16 human adipose tissue samples analyzed, 5 contained tris(1,3-dichloropropyl) phosphate in the range of 0.5 to 110 ng/g, 4 contained tributoxyethyl phosphate in the range of 4.0 to 26.8 ng/g, and one contained tributyl phosphate at 9.0 ng/g.