Nitrogen dioxide and asthma outbreaks.
Explore the source record for details and available documents.
Air Pollutants↗
Biomedical subjects
J Sunyer
Publications and source records attributed to J Sunyer.
A point-source asthma outbreak.
Epidemiological data for the eighth asthma epidemic in Barcelona were available from the whole city. They reveal a striking space clustering, an hour-time clustering, and simultaneous time and space clustering, which indicate that the outbreak was a point-source epidemic. Air pollution by smoke and oxides of sulphur and nitrogen was unlikely to have been the cause of the epidemic, as was an unusual level of pollen or fungal spores. The industrial area adjacent to the neighbourhood in which the epidemic occurred was a probable source of the cause of the outbreak.
Acute Disease↗
Levels of hexachlorobenzene and other organochlorine compounds in cord blood: exposure across placenta.
Hexachlorobenzene (HCB) is an organochlorine compound widespread in the environment, highly lipophilic, that accumulates in biological systems. It has been suggested that it should be classified as a dioxin-like compound. Newborns are exposed to organochlorine compounds across the placenta and through breastfeeding. Although HCB is one of the most common organochlorine compounds, the transplacental transference of HCB from mother to fetus during pregnancy has been scarcely documented. This study reports the levels of HCB, dichlorodiphenyl trichloroethane (DDT) and its metabolite p,p'DDE, polychlorinated biphenyls (PCBs), and beta-hexachlorocyclohexane (beta-HCH) in 72 maternal blood samples at delivery and in 69 cord blood samples, from which 62 corresponded to mother infant pairs born between May 1997 and September 1999 in a rural area highly exposed to HCB. Results show that all newborns presented detectable levels of HCB, PCBs, and p,p'DDE, and, to a lesser extent, of beta-HCH, the HCB levels being the highest. The geometric mean of HCB was 1.1 ng/ml, ranging from 0.3 to 5.7 ng/ml. Concentrations of HCB levels in cord blood (log ng/ml) were positively associated with concentrations in maternal blood (log ng/ml) (coefficient = 0.45, P < 0.01). Gestational age was not associated with the transplacental transfer of HCB. Maternal p,p'DDE and beta-HCH levels were also associated with newborn levels, but levels of PCBs were not. We conclude that HCB, similar to other organochlorinated compounds, has a transplacental transfer.
Adult↗
[Concentrations of persistent toxic compounds in the Spanish population: a puzzle without pieces and the protection of public health].
The contamination by persistent toxic compounds (PTCs) of the general population is a fact of relevance from a public health perspective. It is also relevant to health care professionals, as well as for environmental, food, industrial and economic policies. Though in Spain information on food contamination by PTCs shows large time and geographic gaps, the scarcity of data is even more severe on the concentrations that PTCs have in people: a representative study of a general healthy population living in a wide geographic area has never been conducted in the country. However, the available studies indicate that around 80-100% of the population has detectable concentrations of DDE, PCBs, hexachlorbenzene or lindane. Studies on the effects that PTCs have upon humans are extremely infrequent in Spain. Yet, the international literature suggests that some PTCs may induce significant biological and clinical effects at doses below those traditionally deemed "safe". The mechanism of action of PTCs are not restricted to endocrine disruption. Assessing the clinical and social relevance of the more subtle and long-term effects of PTCs presents interesting challenges and opportunities. Spain and other European countries lack population indicators on the impact that environmental processes have on human health. Several government levels have a role to fulfill in the monitoring of biological levels of PTCs among persons in order to assess the risks of adverse health effects. Along with over a hundred other countries. Spain will soon try to implement the Stockholm treaty on persistent organic pollutants (POPs). This constitutes a new opportunity to develop more efficient policies to control PTC residues in food, humans and the environment. As part of the treaty implementation it is necessary to launch a Report on factors that influence body concentrations of PTCs in the Spain general population.
Animals↗
[Changes in concentrations of organochloride compounds in women from Flix, Tarragona [Spain]].
The population of Flix (region of Ribera del Ebro, Tarragona) is highly exposed to hexachlorobenzene (HCB) due to the closeness of an electrochemical factory. Although the degree of HCB contamination in this population is still high, concentrations of HCB in the sera of women aged 18-40 years from 1997 to 1999 were 61% lower than those observed in 1994 (4.1 ng/ml vs. 10.6 ng/ml). Concentrations of dichlorodiphenyl dichloroethane (p,p'-DDE) and beta-hexachlorocyclohexane (beta-HCH) also decreased, although the difference was not statistically significant. In contrast, concentrations of polychlorinated biphenyls (PCB) in the period 1997-1999 showed a nonsignificant increase compared with those in 1994.
Adolescent↗
[Features and functions of environmental epidemiology].
The interest of epidemiology in the environmental effects has grown up in recent years. The present paper discusses the role of environmental epidemiology based on a revision of the medical literature appeared in 1989, and on a review of the strategy in setting up standards. Different aspects of the exposure measure, the main characteristic of environmental epidemiology are presented.
Environmental Exposure↗
[Relationship between ideology and efficiency of health care systems. Notes on the reform of the Spanish health care system].
This paper explores the relation between ideology and efficiency of the health care systems. In order to achieve this goal, this study: analyzes the relation between ideology and health care system organization, defines the concept of health care system efficiency, and reviews the relation between health care organization and efficiency. The last part of the paper is devoted to discuss the relevance of the conclusions of the above mentioned analyses to the debate on the reform of the Spanish National Health Care System.
Delivery of Health Care↗
[The evolution of mortality due to asthma in the age groups 5-34 and 5-44. Spain, 1975-1991].
UNLABELLED: BASICS: Mortality caused by asthma has increased in most occidental countries, but its evolution has been unknown for Spain during the last few years. METHOD: Variations of mortality caused by asthma of the age groups from 5 to 44 (age in which it is considered an avoidable cause) and from 5 to 34 years of age (when the diagnosis of disease by asthma is more valid) are analysed in Spain from 1975 to 1991. The data of diseases by asthma (CIE-9th-493) have been supplied by the National Institute of Statistics. RESULTS: The rates of crude mortality by asthma, +/- standard error, for the group from 5 to 34 years of age oscillate between 0.09 +/- 0.02 every 100,000 inhabitants in 1979 to 0.30 +/- 0.04 in 1989. With the standardized rates according to age, we could observe an increase in the mortality caused by asthma for the group from 5 to 34 years of age in 1% (confidence interval 95%, 0.2% to 1.9%) each year since 1981. This increase is not significant for the group from 5 to 44 years of age: 0.6% (IC95% -0.01 to 1.3), due to a negative tendency in the group from 35 to 44 years of age. In the period 1987-1989 there was a significant increase in the group from 5 to 34 years of age (p < 0.001) which could not be explained by the temporary tendency. CONCLUSIONS: We conclude that mortality caused by asthma in these age groups in Spain is infrequent and the rates stay between the lowest registered in the developed world, although, as in most countries, there is a slight increase in the age from 5 to 34 years. The increase of the prevalence and severity of asthma could explain such increase, but this would require specific studies.
Adolescent↗
[Social class differences in bladder cancer in Catalonia].
OBJECTIVE: To assess the presence of socio-economic differences in bladder cancer in a heavily industrialised area of Catalonia, Spain and to evaluate risk factors associated with the presence of these differences. METHODS: 218 cases and 344 population controls resident in the area of Vallès Occidental, Barcelona, were identified prospectively and interviewed during 1993-1995. Socio-economic level was evaluated through attained education and social class on the basis of the last and longest held occupation. Logistic regression was used to derive adjusted odds ratios and 95% confidence intervals. RESULTS: There was no association between education and bladder cancer risk. Social class, evaluated on the basis of longest held job, was weakly related with bladder cancer, with the highest risk occurring in the highest social classes. This pattern was more pronounced when the analysis was done using the last occupation. Occupational exposures modified minimally these results. Among controls, the overall prevalence of smoking did not differ between social class but the prevalence of heavy-smokers (> 48.76 packs-year) was highest among subjects in social class V (35.5%) and lowest in social class I (10%). Adjusting for smoking enlarged social class differences. CONCLUSION: Similarly to the pattern in other European countries, no pronounced differences by social class were observed for bladder cancer in this area of Catalonia. The evaluation of social class patterns was crucially affected by the type of socioeconomic information examined. Measures of life-time experience should be preferred rather than socio-economic level at the time of the disease. Smoking seems to be one of the main mediators for the occurrence of bladder cancer differentials but other, yet unidentified risk factors, must be associated with bladder cancer risk, especially among the highest social classes.
Aged↗
Health effects of chronic high exposure to hexachlorobenzene in a general population sample.
Hexachlorobenzene, an organochlorine compound that accumulates in humans, is widespread throughout the environment. In this study, we describe the health status of inhabitants of a rural village that surrounds an electrochemical factory characterized by high levels of hexachlorobenzene in the air. During 1994, we conducted a cross-sectional study of 1 800 inhabitants in the south of Catalonia, Spain, who were older than 14 y of age. We obtained information on lifestyles and occupational and medical histories via questionnaire. Self-reported health outcomes were validated against clinical records and cancer registry data. Serum levels of hexachlorobenzene were very high in males who worked in the electrochemical factory (geometric mean = 54.6 ng/ml in randomized participants). Levels were lower among subjects who had never worked in the electrochemical factory (females, 14.9 ng/ml; males, 9.0 ng/ml). Levels of other organochlorine compounds (i.e., beta-hexachlorocy-clohexane, 2,2-bis[p-chlorophenyl]-1,1-dichloroethylene) were in the same range found in other communities. Perceived health, prevalence of self-reported common chronic conditions, and porphyria cutanea tarda, thyroid pathology, Parkinson's disease, cancer, and reproductive outcomes were within the ranges observed in other studies. Employment in the plant, however, was associated with having any of the a priori selected health outcomes that were potentially related to exposure to hexachlorobenzene (odds ratio for cancer prevalence = 1.9; 95% confidence interval = 0.5, 7.6). Our population of workers and nonworkers had the highest levels of hexachlorobenzene ever described. The results suggest that exposure to hexachlorobenzene did not affect the general health status of the this population, but it was associated with specific health effects of the most highly exposed subjects.
Adolescent↗
[The EMECAM study on the effects of air pollution. Estudio Multicéntrico Español sobre la Contaminación Atmosférica y la Mortalidad].
Explore the source record for details and available documents.
Air Pollution↗