Little attention has been devoted to the effects on children's respiratory health of exposure to sulphur dioxide (SO2) in ambient air from local industrial emissions. Most studies on the effects of SO(2) have assessed its impact as part of the regional ambient air pollutant mix.
To examine the association between exposure to stack emissions of SO(2) from petroleum refineries located in Montreal's (Quebec) east-end industrial complex and the prevalence of active asthma and poor asthma control among children living nearby.
The present cross-sectional study used data from a respiratory health survey of Montreal children six months to 12 years of age conducted in 2006. Of 7964 eligible households that completed the survey, 842 children between six months and 12 years of age lived in an area impacted by refinery emissions. Ambient SO(2) exposure levels were estimated using dispersion modelling. Log-binomial regression models were used to estimate crude and adjusted prevalence ratios (PRs) and 95% CIs for the association between yearly school and residential SO(2) exposure estimates and asthma outcomes. Adjustments were made for child's age, sex, parental history of atopy and tobacco smoke exposure at home.
The adjusted PR for the association between active asthma and SO(2) levels was 1.14 (95% CI 0.94 to 1.39) per interquartile range increase in modelled annual SO(2). The effect on poor asthma control was greater (PR=1.39 per interquartile range increase in modelled SO(2) [95% CI 1.00 to 1.94]).
Results of the present study suggest a relationship between exposure to refinery stack emissions of SO(2) and the prevalence of active and poor asthma control in children who live and attend school in proximity to refineries.
It has been suggested that airway irritation, by acting as an adjuvant, as well as producing damage, may be an important factor related to asthma. The present study examined the window of time following acute upper and lower airway irritant exposure to determine the period of increased risk of immunological sensitization. Brown Norway rats were exposed to 87 ppm NO2 or 1000 ppm NH3 for 1 hr. A 30-min ovalbumin (OVA) exposure of 18.14 microg/liter air was given at various times based upon the time course of irritant associated inflammatory response (either immediately prior to or 1 or 7 days after the irritant exposure). OVA-only, NO2-only or NH3-only controls, and saline controls were also studied. Weekly booster exposures of OVA (or saline) were given. Circulating OVA-specific IgE, IgA, and IgG levels were quantified periodically during the 6 weeks of the study. Bronchoalveolar lavage (BAL) was also performed to examine the inflammatory response to allergic and irritant challenge. Significant increases in OVA-specific IgE, IgG, and IgA antibody titers were seen in rats given the sensitizing OVA exposure within 1 day of the NO2, but not NH3 exposures. Enhancement of cellular infiltrate in BAL was noted in groups given the sensitizing OVA exposure within 1 day of the NO2 or NH3. It is concluded that the inflammatory and immunological response to antigen exposure can be modified by the site of respiratory tract irritation and the relative times of irritant and antigen exposure.
Occupational asthma is an avoidable form of asthma. In Finland, the diagnosis of occupational asthma entitles substantial compensation to the employee. The diagnostics are based on symptoms, exposure assessment, allergologic investigations, follow-up of peak expiratory flow (PEF) at work and at home and, in many cases, specific challenge tests.
To study the causative agents of occupational asthma in Finland.
The causative agents and the numbers of new occupational asthma cases notified to the Finnish Register of Occupational Diseases (FROD) during 1986-2002 are reported.
The number of occupational asthma cases increased from 1986 until 1995, after which a downward trend, stabilizing during the last few years, has been observed. The majority of the cases (59%) in the beginning of the period (1986-1990) were associated with agriculture, but the percentage has fallen thereafter (42% of the cases in 1998-2002) along with the fall in the total number of cases. Since 1995, indoor moulds from water-damaged buildings have caused an increasing number of cases and have become the most important causative agents (0.5% cases, in 1986-1990 and 18% of the cases in 1998-2002). Chemicals have caused 10-30% of the cases, a decreasing number since 1990. The most important chemicals causing occupational asthma have been diisocyanates and welding fumes, followed by hairdressing chemicals and formaldehyde.
The number of occupational asthma cases in Finland reached its height in the mid-1990s. The decrease in the number of total cases is because of the decrease in agriculture-associated cases, reflecting the number of employees in agriculture-associated occupations, which has greatly decreased since Finland joined the EU in 1995. An epidemic of mould-induced asthma, affecting mostly white-collar employees working in moisture-damaged buildings, has taken place since 1995.
BACKGROUND: Particulate air pollution has been much discussed in Norway during the last few years. Coarse particles from asphalt are likely to have quite different properties than the far smaller particles from diesel exhaust. MATERIALS AND METHODS: On the basis of data from the literature and our own research, we discuss the health problem of different types of particles with a focus on allergy and respiratory symptoms. RESULTS: Diesel exhaust particles have well-documented adverse effects in relation to allergic airway disease. They increase symptoms load in already allergic individuals and also seem to contribute to the increased prevalence of allergy. PM10 is today measured on the basis of weight, not on number. Diesel exhaust particles are much smaller than road surface particles; hence PM10 measurements reflect road surface dust pollution more than exhaust particles. INTERPRETATION: Focus should now be given to diesel exhaust particles in order to reduce the adverse health effects of particulate air pollution in Norwegian cities.
Comment In: Tidsskr Nor Laegeforen. 2002 Aug 10;122(18):176612362683
Many investigations suggest that a high degree of air-borne pollution increases the prevalence of diseases like asthma and eczema. SÃ¸r-Varanger Municipality in Finnmark County in the north of Norway receives much air-borne pollution from domestic industry and from the metallurgic industry on the Kola peninsula in North-Western Russia. We have investigated indirect parameters of morbidity caused by asthma and eczema by analyzing data on drug consumption and hospital admissions. In SÃ¸r-Varanger there is high consumption of corticosteroids for dermatological use. Consumption of anti-asthmatic drugs and number of admissions to hospital for asthma and eczema were no higher than expected. We suspect that air-borne pollution, particularly the heavy metal nickel, increases the prevalence and perhaps worsens the degree of eczema in SÃ¸r-Varanger.
Atmospheric pollution has been proposed as one of the possible factors responsible for increases in asthma mortality and morbidity.
We sought to examine whether we could demonstrate a relationship between emergency room visits for asthma and alterations in environmental conditions.
Over a 1-year period, the frequency of emergency room visits for asthma in a large urban hospital were documented and compared to outdoor concentrations of SO2, NO2, and ozone in addition to two overall measures of air quality (air pollution index and air quality index).
A total of 854 emergency room visits were noted with the highest number of visits occurring in May and between September and December. Significant variations in the frequency of visits as well as environmental conditions could be seen on a daily basis. Despite comparisons of results on a daily, weekly, and monthly basis, no significant relationships could be found between any of the pollution indices and emergency room visits. Staggering visits by 1 and 7 days, however, revealed a relationship between emergency room visits and air pollution index and air quality index. An association between emergency room visits and NO2 and ozone was seen when visits were staggered by 7 but not by 1 day.
We conclude the fluctuations in overall air quality are associated with increased frequency of emergency room visits but only when data are lagged by a predefined period.
High-dose exposure to inorganic mercury in man can influence the immune system and in rare cases cause immune-related disease. Some experimental animals also react with autoimmunity after low doses of inorganic mercury. Glomerulonephritis and an increased formation of immunoglobulin type E (IgE) are characteristic of these reactions. A recent study of 15-year-old adolescents demonstrated an association between immunoglobulin type A (IgA) and mercury concentration in plasma (P-Hg). There was also an association between allergic disease and IgA levels. The present study included 54 male and 23 female 19-year-old students who were recruited from a cohort that had been previously defined in a survey of allergic disease. Of the students, 39 (51%) had asthma, allergic rhinoconjunctivitis or eczema. Similar amalgam burden and P-Hg levels were observed in students with (n = 39) and without (n = 38) allergic disease (P = 0.48 and P = 0.98, respectively). As expected, IgE levels were significantly higher in the group with allergic disease (P = 0.006), but there was no association between P-Hg and IgE. The P-Hg levels were very low (median 1.50 nmol/l) and correlated significantly (r = 0.31) with the small number of amalgam surfaces (P = 0.007). Thirty-seven students had no amalgam fillings. P-Hg levels did not associate significantly with IgA, but did so with IgG2 (r = 0.33; P = 0.003). No conclusive correlation was observed between IgG2 and amalgam fillings. The findings of this study in 19-year-old subjects differ from earlier data obtained in a sample 4 years younger. The possibility of chance in the association between P-Hg levels and IgG2 must, however, be considered.