Lead, mercury, and organochlorine compound levels in cord blood in Québec, Canada

We conducted this study to evaluate blood levels of lead, mercury, and organochlorine compounds in newborns in the Province of Quebec. During 1993 to 1995, we carried out a survey in 10 hospitals located in southern Quebec. During that time, umbilical cord blood samples were obtained from 1109 newborns, and we analyzed each for lead, mercury, 14 polychlorinated biphenyl congeners, and 11 chlorinated pesticides. We used the geometric mean and 95% confidence interval (CI) to describe the results. Mean concentrations of lead and mercury in cord blood were 0.076 micromol/l (95% CI = 0.074, 0.079) and 4.82 nmol/l (95% CI = 4.56, 5.08), respectively. The mean concentrations of total polychlorinated biphenyls (Aroclor 1260) and dichlorodiphenyl dichloroethylene were 0.514 microg/I (95% CI = .493, 0.536) and 0.412 microg/l (95% CI = 0.390, 0.435), respectively. We observed a statistically significant relationship between maternal age and cord blood concentrations of (a) lead, (b) mercury, (c) polychlorinated biphenyls, and (d) dichlorodiphenyl dichloroethylene. In addition, maternal smoking during pregnancy was associated with cord blood lead levels. The cord blood concentrations of lead, mercury, polychlorinated biphenyls, and dichlorodiphenyl dichloroethylene we measured in our study were the lowest levels recently reported in industrialized countries. The results of this study underline the role of public health authorities in the evaluation of biological levels of environmental contaminants among children for the assessment of risk of adverse health effects.     

Gonotrophic cycle estimate for Culex quinquefasciatus in Mérida, Yucatán, México

West Nile virus (WNV) has been present in the Yucatán State, México, since 2002. Culex quinquefasciatus, one of the main vectors of WNV transmission in the United States, is also common in Mexico and may be a key vector of WNV transmission t o humans in t he Yucatán. The aim of this study was to determine the length of the gonotrophic cycle and the survival rates of Cx. quinquefasciatus from Mérida, Yucatán, during the rainy versus the dry season. Mosquitoes were collected during 25-day periods in October (rainy season) and in April (dry season), and captured females were classified by abdominal appearance (freshly fed, late-stage fed, half gravid, and subgravid). To determine the age structure as nulliparous and parous females and to calculate the gonotrophic cycle through a time series and the mosquito survival, we used Davidson formulae. Also, vitellogenesis analysis to monitor egg maturity was conducted during both seasons. Cross-correlation data suggested a similar length of the gonotrophic cycle (4 days) in both seasons. Oogenic development required a minimum of 72 h in each season. However, survival of the mosquito population collected in the rainy season was significantly higher (0.91) with a mean temperature of 28 +/- 1.57 degrees C than was survival in the dry season (0.78) with a mean temperature of 29 +/- 1.10 degrees C. Survival, although higher during the rainy season, did not influence the length of the gonotrophic cycle of Cx. quinquefasciatus in Yucatán.     

Vasectomy and prostate cancer in Québec, Canada

The present investigation measured the association between vasectomy and prostate cancer (PC) in the male population of Québec, Canada. The Québec Health Insurance Board and the Québec Cancer Registry were our principal sources of information. Lung cancer cases and the male population of Québec served as controls for comparative purposes. Within a retrospective design, our preliminary results indicate an association between vasectomy and PC. Among the 1925-39 birth cohort of individuals diagnosed with PC in 1990--93, the global odds ratio was 2.6 (95% CI=1.7--4.3) while it was compared with lung cancer as the control group. This risk increased with the length of time between vasectomy and the diagnosis of cancer. An historical design indicated strong cohesion of the results. Besides, the risk does not vary when we control for the place of residence of the individuals. Vasectomy seems to increase the risk of PC at least 10 years after the operation, but we cannot exclude the impact of a possible detection bias among vasectomized individuals.     

Neighbourhood influences on health in Montréal, Canada

This paper examines neighbourhood effects on health within a large Canadian city--Montréal. Our approach is to consider that individual health outcomes are determined both by individual and neighbourhood characteristics and we consciously take on the problem of neighbourhood definition by developing 'natural' neighbourhoods. Our data come from the Montréal health region sample of the 2000/1 Canadian Community Health Survey, a comprehensive national survey that contains information on health outcomes as well as behavioural and socio-demographic information. Respondents were placed into 'naturally' defined neighbourhoods as opposed to arbitrary geostatistical units, responding to calls in the literature to develop more meaningful units of analysis. We also compare the 'natural' neighbourhood approach with the use of standard census tracts as the unit of analysis. Results show significant between-neighbourhood variation in health status with about 3% of the variance in the Health Utilities Index captured at the neighbourhood level, even after controlling for a variety of socio-demographic and behavioural variables at the individual level. Models using census tracts as the unit of analysis had remarkably similar results to the 'natural' neighbourhood models, suggesting that census tracts are good proxies for natural neighbourhood boundaries in studies of neighbourhood effects on health.     

Dengue epidemic in Belém, Pará, Brazil, 1996-97

We describe clinical and epidemiologic findings during the first epidemic of dengue fever in Belém, Pará State, Brazil, in 1996-97. Of 40,237 serum samples, 17,440 (43%) were positive for dengue by virus isolation or serologic testing. No hemorrhagic cases or deaths were reported. Mycobacterium tuberculosis     

Carbon monoxide exposure in households in Ciudad Juárez, México

This study assessed exposure to carbon monoxide from gas and wood heater emissions in a sample of 64 households in peri-urban residential areas in Ciudad Juárez, Chihuahua, México. Indoor and outdoor carbon monoxide concentrations and temperatures were monitored for a continuous period of 1 week at 1 and 6-min intervals, respectively. The moving average carbon monoxide concentrations were compared to the World Health Organization (WHO) standards for carbon monoxide. Sixty-seven percent of households with gas heaters and 60% of households with wood heaters exceeded a health-based standard at some point during the monitoring. The difference between indoor and outdoor temperatures was modestly correlated with average carbon monoxide exposure (r=0.35, p-value <0.01). Heater type may be a stronger determinant of exposure, as households with a particular heater model (the El Sol FM-210) were significantly more likely to be among the more highly exposed households (odds ratio of 4.8, p-value of 0.02). A variety of health effects were pooled and found at elevated frequency in the households that exceeded the 8-h standard of 9 ppm (odds ratio=5.1, p-value=0.031). These results highlight the need for further efforts to identify and mitigate potentially hazardous carbon monoxide exposures, particularly in moderate-income countries with cooler climates.     

Occurrence of pesticides in the Yamaska River,Québec

Concentrations of pesticides in water near the mouths of the Yamaska River in Québec, Canada, and five of its tributaries are reported for the summers of 1986 and 1987. The most frequently occurring pesticides, and those at the highest concentrations, were atrazine and metolachlor. Peak atrazine concentrations frequently exceeded the recommended Canadian water quality guideline of 2 g/L for the protection of aquatic life. These peak concentrations were similar to those that had been observed a decade before. In addition, in 1986 and 1987 significant concentrations of metolachlor were detected in the waters. In some locations, the peak metolachlor concentration was greater than half its recommended Canadian water quality guideline of 8 g/L for the protection of aquatic life, and in one location the guideline was exceeded. Also found at much lower concentrations were some other triazine herbicides, some degradation products of triazine herbicides, and some organophosphorus and organochlorine insecticides. No carbamate pesticides were found.Deceased     

Installation of a Bridge Barrier as a Suicide Prevention Strategy in Montréal,Québec,Canada

Objectives. We investigated whether the installation of a suicide prevention barrier on Jacques-Cartier Bridge led to displacement of suicides to other jumping sites on Montréal Island and Montérégie, Québec, the 2 regions it connects.Methods. Suicides on Montréal Island and Montérégie were extracted from chief coroners’ records. We used Poisson regression to assess changes in annual suicide rates by jumping from Jacques-Cartier Bridge and from other bridges and other sites and by other methods before (1990–June 2004) and after (2005–2009) installation of the barrier.Results. Suicide rates by jumping from Jacques-Cartier Bridge decreased after installation of the barrier (incidence rate ratio [IRR] = 0.24; 95% confidence interval [CI] = 0.13, 0.43), which persisted when all bridges (IRR = 0.39; 95% CI = 0.27, 0.55) and all jumping sites (IRR = 0.66; 95% CI = 0.54, 0.80) in the regions were considered.Conclusions. Little or no displacement to other jumping sites may occur after installation of a barrier at an iconic site such as Jacques-Cartier Bridge. A barrier’s design is important to its effectiveness and should be considered for new bridges with the potential to become symbolic suicide sites.Physical availability and sociocultural acceptability are important considerations in the choice of method of suicide.1 Restricting access to commonly used methods of suicide is widely recognized as a suicide prevention strategy. Several studies have indicated that detoxification of domestic gas; mandatory use of catalytic converters in motor vehicles; restrictions on pesticides, barbiturates, and analgesics; use of lower toxicity antidepressants; firearm control legislation; and construction of barriers at jumping sites have been effective in reducing suicides by those methods.1 However, evidence for the success of some of these strategies remains equivocal (e.g., use of catalytic converters in Australia,2 reduction of paracetamol pack size in the United Kingdom3,4). Furthermore, restricting one method can result in substitution with another, although substitution may depend on the popularity of the method and the availability of alternative methods that are acceptable to the individual.5–7 A change in overall suicide rates may be obscured if method substitution occurs or if the restricted suicide method accounts for a relatively small proportion of all suicides.1,8For suicide by jumping, displacement to other jumping sites is probably more likely than a change in method. Two studies found no shift to other jumping sites after installation of barriers, but they did not examine the effect on overall suicide rates.9,10 By contrast, other studies have shown evidence of displacement, with overall suicide rates remaining unchanged.11–13 In 1 of these latter studies, jumping suicides from other bridges and buildings in Toronto increased after the construction of a suicide barrier at Bloor Street Viaduct.13 The researchers suggested that the viaduct was not a uniquely attractive location for suicide and was therefore interchangeable with other sites. By contrast, some jumping sites are reportedly the only site a suicidal individual would consider (e.g., Golden Gate Bridge, Eiffel Tower, Empire State Building); their status as suicide magnets is enhanced by the ease of access, perceived lethality of the jump, notoriety as a popular suicide site, romantic view of death they encourage, media attention, and unique features such as being over water.10,13–16All of these factors existed for Jacques-Cartier Bridge, which spans the St. Lawrence River between Montréal Island and Montérégie, Québec, with an average of 10 suicides annually before the construction of a barrier in 2004 (P-A Perron, unpublished data, 2002). To create the barrier, the existing 1.1-meter steel palisade fencing was extended a further 1.4 meters and curved inwardly at the top, making it high and difficult to climb (see image available as a supplement to the online version of this article at http://www.ajph.org). An initiative to have a barrier installed was unsuccessful in 1996 and almost halted in 2002 because of the argument that a barrier would not decrease suicides but merely displace them to other sites. To test the validity of this argument, we assessed whether displacement to other jumping sites on Montréal Island and Montérégie occurred.     

Work-related mesothelioma in Québec, 1967-1990.

Prior surveys of malignant mesothelioma in Québec have noted that almost all the excess in occupational exposure related mesothelioma was in the manufacture and industrial application of asbestos rather than in the mining and milling operations. To evaluate the current status of malignant pleural mesothelioma in the Québec workforce, we reviewed all cases of pleural mesothelioma seen and accepted by the Québec Workman's Compensation Board (CSST) for work related compensation of industrial disease. We identified 120 cases, 7 of whom were females. They were of an average age of 59 +/- 8.5 yrs (sd) (range 42-84); they were exposed to asbestos dust in the workplace for an average of 26 +/- 14.3 yrs (range 0.5-50). The cases were subdivided into 3 groups according to workplace asbestos exposures. There were 49 cases originating in the mines and mills of the Québec Eastern Township region (primary industry, group 1), 50 cases from the manufacture and industrial application sector (secondary industry, group 2), and 21 cases from industries where asbestos was not a major work material, often an "incidental" material (tertiary industry, group 3). Group 1 was of an average age of 62 +/- 8 years, exposed to asbestos dust 31 +/- 14 years and the distribution of exposure time was as follows: 15% cases with < or = 10 year-exposure and 77% > or = 25 year-exposure. In group 2, the age was significantly lower at 57 +/- 9 years; the exposure time was also significantly lower at 22 +/- 14 years, and the distribution of exposure time differed from the above (29% cases with < or = 10 year-exposure and 48% > or = 25 year-exposure). In group 3, the average age was 58 +/- 7 years, the exposure time was also significantly lower at 28 +/- 12 years and the distribution of exposure time differed from the above (33% cases with < or = 10 year-exposure and 62% > or = 25 year-exposure). Analyses of the yearly incidence of new cases in each group documented the general incremental trend in all groups, with the sharpest rises in group 3. In the mining towns of Thetford and Asbestos, the incidence of mesothelioma was proportional to the workforce, thus suggesting that the tremolite air contamination, which is 7.5 x higher in Thetford, may not be a significant determinant of the disease in these workers.(ABSTRACT TRUNCATED AT 400 WORDS)     

Informal recycling and occupational health in Santo André, Brazil

The collection of recyclables is a widespread activity among urban poor, particularly in countries with large socio-economic disparities. The health of recyclers is at risk because of unsafe working conditions, socio-economic exclusion, and stigmatization. Our study focuses on health problems and occupational risks of informal recyclers (in Brazil known as catadores). In 2005 we conducted an in-depth socio-economic survey of 48 informal waste collectors in Santo André, Brazil. Almost all workers reported body pain or soreness in the back, legs, shoulders, and arms. Injuries, particularly involving the hands, are frequent. Flu and bronchitis are common, and one recycler had contracted Hepatitis-B. Policy makers at all government levels need to address the pressing health issues affecting large numbers of informal recyclers in Brazil and abroad. Recyclers need to be involved in the design of waste management policies, and the public must be educated about the important environmental service these people provide.     

Perceptions,health care seeking behaviour and implementation of a tuberculosis control programme in Lambaréné, Gabon

Setting:

Lambaréné, Gabon.

Objectives:

To describe patient perceptions of tuberculosis (TB) and to determine factors that influence health care seeking behaviour to gain insight into the management of multidrug-resistant TB.

Design:

Participant observation, in-depth semi-structured interviews and focus group discussions were conducted with 30 TB patients, 36 relatives, 11 health care providers and 18 traditional/spiritual healers. Recruitment of patients was linked to the PanEpi study and took place at the Albert Schweitzer Hospital, the General Hospital and the TB-HIV (human immunodeficiency virus) clinic.

Results:

Patients generally described TB as a natural and/or magical disease. The majority of the patients combined treatment at the hospital with (herbal) self-treatment and traditional/spiritual healing. Despite the free availability of anti-tuberculosis treatment in principle, patient adherence was problematic, hindering effective TB control. Most patients delayed or defaulted from treatment due to financial constraints, stigmatisation, ignorance about treatment, change of health care service or use of non-prescribed antibiotics. The situation was occasionally complicated by drug stockouts.

Conclusion:

There is an urgent need to bridge the gap between patients and the hospital by avoiding drug shortages, intensifying culturally sensitive TB health education, embedding TB care into the cultural context and enhancing cooperation between hospitals, patients, traditional healers and communities.     

Comparison of in vivo and in vitro tests of resistance in patients treated with chloroquine in Yaoundé, Cameroon

The usefulness of an isotopic in vitro assay in the field was evaluated by comparing its results with the therapeutic response determined by the simplified WHO in vivo test in symptomatic Cameroonian patients treated with chloroquine. Of the 117 enrolled patients, 102 (87%) completed the 14-day follow-up, and 95 isolates obtained from these patients (46 children, 49 adults) yielded an interpretable in vitro test. A total of 57 of 95 patients (60%; 28 children and 29 adults) had an adequate clinical response with negative smears (n = 46) or with an asymptomatic parasitaemia (n = 11) on day 7 and/or day 14. The geometric mean 50% inhibitory concentration of the isolates obtained from these patients was 63.3 nmol/l. Late and early treatment failure was observed in 29 (30.5%) and 9 (9.5%) patients, respectively. The geometric mean 50% inhibitory concentrations of the corresponding isolates were 173 nmol/l and 302 nmol/l. Among the patients responding with late and early treatment failure, five isolates and one isolate, respectively, yielded a discordant result (in vivo resistance and in vitro sensitivity). The sensitivity, specificity, and predictive value of the in vitro test to detect chloroquine-sensitive cases was 67%, 84% and 86%, respectively. There was moderate concordance between the in vitro and in vivo tests (kappa value = 0.48). The in vitro assay agrees relatively well with the therapeutic response and excludes several host factors that influence the results of the in vivo test. However, in view of some discordant results, the in vitro test cannot substitute for in vivo data on therapeutic efficacy. The only reliable definition of "resistance" in malaria parasites is based on clinical and parasitological response in symptomatic patients, and the in vivo test provides the standard method to determine drug sensitivity or resistance as well as to guide national drug policies.     

Rising Disparities in Severe Adverse Birth Outcomes Among Haitians in Québec, Canada, 1981–2006

Perinatal health data for Haitians are scant. We evaluated adverse birth outcomes for Haitians in Québec, Canada. We analyzed 2,124,909 live births from 1981 to 2006. Haitian ethnicity was assessed using maternal birth country (Haiti, other Caribbean country, other foreign country, Canada) and home language (Creole, French/English but Creole mother tongue, French/English, other). Associations between ethnicity and preterm birth (PTB), low birth weight (LBW), and small-for-gestational-age (SGA) birth were calculated. Adverse birth outcomes were more common among mothers with Haitian ethnicity. Relative to Canadian-born mothers, odds for Haitian-born mothers were 4 times greater for extreme PTB (≤27 weeks), twice greater for very PTB (28–31 weeks), and 25% higher for moderate PTB (32–36 weeks). Patterns were similar for SGA birth and severe cases of LBW. Despite overall decreases LBW and SGA birth, relative and absolute inequalities increased over time. Perinatal health inequalities are increasing for Haitian-born mothers.     

Health Risks Associated With Pesticide Residues in Sediments, Fish, and Plants From the Ouémé Valley in the Republic of Bénin

To determine possible human and environmental health risks, organochlorine pesticide residues were determined in vegetables grown in floodplains along the Ouémé River near Lowé in Bénin. Testing of vegetables found 13 pesticides with ΣDDT, α-endosulfan, Σdrin, and lindane being most important. The same pesticides were also detected in plants eaten by bovine cattle, sheep, and herbivorous fish. Human pesticide intake by vegetable consumption was compared with tolerable daily intake (TDI) values reported by the World Health Organization. Pesticide intake by fish consumption was estimated from residue levels in whole fish collected from the Ouémé River in 2004 and reported earlier. Fish consumption does not pose a risk for human health, but consuming vegetables that contain pesticide residues may lead to exceedance of TDI values. Based on these findings, concerns are warranted, and more work is needed to understand the full exposure profile for the local population.