Monitoring of umbilical cord blood lead levels and sources assessment among the Inuit.

Analyses completed on samples collected between 1993 and 1996 showed that about 7% of 475 Inuit newborns from northern Quebec (Canada) had a cord blood lead concentration equal to or greater than 0.48 micromol/l, an intervention level adopted by many governmental agencies. A comparison between the cord blood lead isotope ratios of Inuit and southern Quebec newborns showed that lead sources for these populations were different. Our investigation suggests that lead shots used for game hunting were an important source of lead exposure in the Inuit population. A cohort study conducted in three Inuit communities shows a significant decrease of cord blood lead concentrations after a public health intervention to reduce the use of lead shot. Lead shot ammunition can be a major and preventable source of human exposure to lead.

[1998 Quebec Social and Health Survey: determinants of chronic respiratory diseases]. / Enquête sociale et de santé de 1998 au Québec: divers déterminants des maladies chroniques respiratoires.

In the course of the "1998 Health and Social Survey", questions were included to verify the prevalence of chronic respiratory diseases and also of wheezing. The objectives of this study were 1) to verify the prevalence of wheezing and its validity as an indicator of chronic respiratory diseases in Québec; and 2) to examine the relationship between chronic respiratory diseases and some of their potential determinants. A total of 30,386 individuals participated in the study. For all ages, the prevalence of wheezing was 5.4%. It was associated with asthma, allergies, chronic bronchitis and emphysema. A low familial income and tobacco smoking were associated with wheezing, asthma, chronic bronchitis and emphysema. Passive smoking was associated with wheezing whereas the presence of carpets was associated with wheezing and asthma. Between 32 and 48% of families with an asthmatic or an allergic member modified their dwelling to alleviate respiratory problems. The prevalence of wheezing documented here was lower than in anglosaxon countries. This result could be explained by a cultural factor (the French translation or the perception of wheezing). This study emphasizes the role of reducing tobacco smoking in the prevention of chronic respiratory diseases.

Wood-burning appliances and indoor air quality.

Wood heating represents an interesting economic alternative to electrical or heating oil and gas systems. However, many people are concerned about poor indoor air quality in homes equipped with wood-burning appliances. We conducted a study in the Quebec City region (Canada) to verify the extent of indoor air contamination, and to examine the frequency of respiratory symptoms and illnesses among occupants of wood-heated homes. One child attending primary school (median = 8 years old; range = 5-14 years old) and an adult (median = 37 years old; range = 23-52 years old) were recruited in each eligible house. Eligible houses were without known sources of combustion products (smokers, attached garage, oil or gas furnace, gas stove, etc.) except for wood-burning appliance. Out of the 89 houses included in the study, 59 had wood-burning appliances. Formaldehyde, nitrogen dioxide, respirable particles (PM10) and carbon monoxide were measured in a sub-set of 49 houses (41 with a wood-burning appliance and 8 without). The frequency of respiratory symptoms and diseases among participants were documented using a daily symptom diary. Concentrations of contaminants were low in most houses, both with or without a wood-burning appliance. Globally, there was no consistent relationship between the presence of a wood-burning appliance and respiratory morbidity in residents. Nevertheless, residents who mentioned being exposed to fumes emitted by such an appliance reported more respiratory illnesses and symptoms. The presence of animals or molds, and keeping windows closed most of the time in winter were other factors associated with respiratory problems. We conclude that wood burning appears to be a respiratory health risk for occupants if the appliance is not maintained and used properly.

The efficacy of a broad-spectrum sunscreen to protect engineered human skin from tissue and DNA damage induced by solar ultraviolet exposure.

Sunscreens are known to protect against sunlight-induced erythema and sunburn, but their efficiency at protecting against skin cancer is still a matter of debate. Specifically, the capacity of sunscreens to prevent or reduce tissue and DNA damage has not been thoroughly investigated. The present study was undertaken to assess the ability of a chemical broad-spectrum sunscreen to protect human skin against tissue and DNA damage after solar UV radiation. Engineered human skin was generated and either treated or not with a broad-spectrum SPF 30 sunscreen and exposed to increasing doses of simulated sunlight (SSL). Immediately after irradiation, histological, immunohistochemical, and molecular quantitative analyses were performed. The unprotected irradiated engineered human skin showed significant epidermal disorganization accompanied by a complete absence of laminin deposition. The sunscreen prevented SSL-induced epidermal damage at low doses and allowed laminin deposition at almost all SSL doses tested. The frequencies of cyclobutane pyrimidine dimers, pyrimidine (6-4) pyrimidone photoproducts, and photooxidative lesions measured by alkaline gel electrophoresis and radioimmunoassay were significantly reduced by the sunscreen. Thus, tissue and DNA damage may provide excellent quantitative end points for assessing the photoprotective efficacy of sunscreens.

An unusual case of carbon monoxide poisoning.

Carbon monoxide, a gas originating from incomplete combustion of carbon-based fuels, is an important cause of human deaths. In this paper, we describe an unusual carbon monoxide poisoning in a dwelling without obvious sources of combustion gases, for which two adults had to be treated in a hyperbaric chamber. Carbon monoxide readings were taken in the house and in the neighboring homes. Methane gas and nitrogen oxide levels were also monitored in the house air. Soil samples were collected around the house and tested for hydrocarbon residues. The investigation revealed the presence of a pocket of carbon monoxide under the foundation of the house. The first readings revealed carbon monoxide levels of 500 ppm in the basement. The contamination lasted for a week. The investigation indicated that the probable source of contamination was the use of explosives at a nearby rain sewer construction site. The use of explosives in a residential area can constitute a major source of carbon monoxide for the neighboring populations. This must be investigated, and public health authorities, primary-care physicians, governmental authorities, and users and manufacturers of explosives must be made aware of this problem.

A population-based survey on the use of artificial tanning devices in the Province of Québec, Canada.

BACKGROUND: The suntanning industry has grown up over the last decade in North America, mainly because tanned skin is socially desirable and artificial tanning is perceived as a "safe tan." However, exposure to UV radiation is known to cause adverse health effects. OBJECTIVE: The purpose of this study was to estimate the prevalence of use of tanning equipment in the Province of Québec and to characterize people who reported using these devices. METHODS: In 1996, a telephone survey was carried out among adults from the two most densely populated regions (Montréal, Québec) of the Province of Québec. The final sample included 1003 white persons 18 to 60 years old. Interviewers used a standardized questionnaire to document the characteristics of the participant, skin phototype, and exposure habits to artificial UV radiation sources. RESULTS: During the last 5 years before the survey, 20.2% of the respondents reported they had used, at least once, a tanning device in a commercial tanning salon. The rate of use during the last 12 months before the study was 11.1%. A significantly higher proportion of female, young people (18 to 34 years old) and single persons was found among tanning bed users. Twenty-six percent of users experienced one or more acute adverse health effects from the artificial UV irradiation. Most of these were cases of skin burns. A high proportion (77.5%) of those who used tanning equipment during the last year before the study said they would return to tanning salons. The intention of returning to a tanning salon was not influenced by the occurrence of the acute adverse health effects. The most prevalent reason given for using tanning equipment was "to improve their appearance by a tan." Most people (60.4%) who used a tanning bed during the last 5 years before the study believe that tanning salons are not dangerous. CONCLUSION: This survey indicates that tanning bed use is very prevalent in the Province of Québec, mainly among young women. The high rate of acute adverse health effects related to artificial tanning, particularly skin burns, is of concern. Finally, our results underline the importance of changing attitudes and beliefs in the population regarding artificial tanning.

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.

Effects of maternal cigarette smoking and alcohol consumption on blood lead levels of newborns.

The purpose of this study was to evaluate the effect of cigarette smoking (active and passive exposure) and alcohol consumption during pregnancy on cord blood lead levels. In 1990, a survey was conducted in two hospitals in Québec City, Québec, Canada, a white-collar agglomeration. The sample included 430 mothers and their newborns. Information on the lifestyles of mothers during pregnancy was obtained by questionnaire. Cord blood lead concentrations were measured by atomic absorption spectrophotometry. A dose-response relation was found between cigarette smoking and alcohol consumption of mothers and cord blood lead levels. An average increase of about 15 percent (0.013 mumol/liter) in cord blood lead levels was estimated for every 10 cigarettes smoked per day. Mean blood lead levels in babies whose mothers did not smoke during pregnancy but who drank alcohol moderately was 17 percent higher than those of nonsmoking mothers who abstained from alcohol intake. Multivariate analyses revealed that both cigarette smoking and alcohol intake make significant and independent contributions to cord blood lead concentrations. Lifestyles of pregnant women thus appear to play an important role in the prenatal lead exposure of newborns. Because of the potential effects of lead exposure on pregnancy outcomes, our study provides further arguments to support public health advisories concerning the harmful effect of smoking and drinking alcohol during pregnancy.

Is there a need for systematic blood lead screening in Canadian children?

Neuropsychological effects occurring in young children exposed to low blood lead levels are now better known. This paper reviews the need to systematically screen for blood lead levels compatible with subclinical lead poisoning in young Canadian children. Using standard criteria for judging the appropriateness of this measure, the authors found no evidence to support such a practice in Canada. Case-finding is recommended in clinical settings for children with disorders suggestive of lead poisoning, increased lead absorption or exposure to a potential source of lead. A population survey is also recommended in the presence of a well-documented community environmental lead source. There is a need for common protocols across Canada for evaluating and treating children with blood lead levels compatible with subclinical poisoning. Areas of priority research are: the impact of persistent environmental sources of lead such as old paint and lead in water; defining criteria for selective screening; and methods of cost-effective environmental remediation.

Chiral esters: Sex pheromone of the bagworm,Oiketicus kirbyi (Lepidoptera: Psychidae).

Gas chromatographic-electroantennographic detection (GC-EAD) analyses of pheromone extract of female bagworms,Oiketicus kirbyi (Guilding), revealed five EAD-active compounds. Retention index calculations, GC-mass spectrometry in both full-scan and selected-ion monitoring modes and GC-EAD analyses of authentic standards identified the compounds as 1-methylbutyl octanoate (MBO), 1-methylbutyl nonanoate (MBN), 1-methylbutyl decanoate (MBD), 1-methylpentyl decanoate (MPD), and 1-methylbutyl dodecanoate (MBDD). Of these five chiral esters, MBD was most abundant in extracts and elicited the strongest antennal response. In field experiments in Costa Rica, (R)-MBD attractedO. kirbyi males, whereas (S)-MBD in combination with (R)-MBD inhibited response.R but notS enantiomers of MBO, MBN, and MBDD strongly synergized attraction to (R)-MBD. (S)-MBO and (S)-MBDD were inactive, whereas (S)-MBN was inhibitory. (R)-, (S)- and racemic MPD were inactive. Blends of (R)-MBD in ternary combination with either (R)-MBO and (R)-MBN or (R)-MBN and (R)-MBDD were as attractive as the five-ester blend. Five- and four-ester blends were equally attractive, suggesting redundancy of pheromone components for attraction of males. The multiple sex pheromone component blend of chiral esters inO. kirbyi may have evolved to maintain species-specific communication in bagworm communities of tropical Americas.

Ethyl propionate: Synergistic kairomone for african palm weevil,Rhynchophorus phoenicis L. (Coleoptera: Curculionidae).

Small trunk pieces of a freshly felled 10-year-old oil palm,Elaeis quineensis (Jacq.), were placed in a modified Nalgene desiccator, and volatiles captured for six days on Porapak Q. Gas chromatographic (GC) analysis of Porapak-Q-trapped volatiles with both flame ionization (FID) and electroantennographic detection (EAD) using male or femaleR. phoenicis antennae revealed several EAD-active compounds. They were identified as: ethyl acetate, ethyl propionate, isobutyl propionate, ethyl butyrate, and ethyl isobutyrate. In field experiments in the La Me Research Station, Côte d'Ivoire, ethyl propionate (50 mg/24 hr) but not all esters combined (50 mg/24 hr each) significantly increased capture ofR. phoenicis in pheromone-baited (3 mg/24 hr) traps. One kilogram of 1- to 3-day-old palm tissue was significantly more effective than ethyl propionate in enhancing pheromone attraction. Superior attraction of palm tissue may be attributed to additional as yet unknown semiochemicals. Alternatively, release rates and/or ratios of synthetic volatiles differed from those of palm tissue at peak attraction.

Umbilical cord blood lead levels in the Québec City area.

The purposes of this study were to determine the umbilical cord blood lead levels in a nonindustrialized city and the effect of place of residence on the blood lead levels of newborns. During spring 1990, we conducted a survey of umbilical cord blood lead levels from 823 live newborns in two hospitals from the Québec City area. The geometric mean of cord blood lead levels was 0.094 mumol/l (95% confidence interval [95% CI] = 0.088-0.099). Less than 1% (95% CI = 0.2-1.7) of the babies had cord blood lead levels at 0.48 mumol/l or greater. We estimate that each year in the Québec City area between 150 and 200 newborns are at risk for developing psychoneurological problems during their first years of life. Frequency distribution of cord blood lead level did not differ significantly among urban, suburban, and rural areas; however, a higher proportion of cord blood lead levels greater than 0.25 mumol/l was observed in the urban area (9.4%), compared with suburban (2.6%) and rural (3.1%) areas. The proximity of potential environmental lead sources (highway, industry, city center) located within 1/2 mile (.8 km) of the mother's residence was associated with a high cord blood lead level. Cord blood lead levels were also elevated for newborns whose mothers lived in newer (< or = 5 y) and older buildings (> or = 50 y). We concluded that the environmental characteristics of the mother's residence are a better indicator of environmental lead exposure than the place of residence.(ABSTRACT TRUNCATED AT 250 WORDS)