Marzia Simoni

Indoor air pollution and airway disease.

Scientific interest in indoor pollution has been increasing since the second half of the 1980s. Growing scientific evidence has shown that because people generally spend the majority of their time indoors, indoor pollution plays a significant role in affecting health and is thus an important health issue. Indoor environments include dwellings, workplaces, schools and day care centres, bars, discotheques and vehicles. Common indoor pollutants are environmental tobacco smoke, particulate matter, nitrogen dioxide, carbon monoxide, volatile organic compounds and biological allergens. In developing countries, relevant sources of indoor pollution include biomass and coal burning for cooking and heating. Concentrations of these pollutants can be many times higher indoors than outdoors. Indoor air pollution may increase the risk of irritation phenomena, allergic sensitisation, acute and chronic respiratory disorders and lung function impairment. Recent conservative estimates have shown that 1.5-2 million deaths per year worldwide could be attributed to indoor air pollution. Approximately 1 million of these deaths occur in children aged under 5 years due to acute respiratory infections, and significant proportions of deaths occur due to chronic obstructive pulmonary disease and lung cancer in women. Today, indoor air pollution ranks tenth among preventable risk factors contributing to the global burden of disease. Further research is necessary to better evaluate the respiratory health effects of indoor pollution and to implement protective programmes for public health.

Mould/dampness exposure at home is associated with respiratory disorders in Italian children and adolescents: the SIDRIA-2 Study

Aims: To report on the relation between home mould and/or dampness exposure and respiratory disorders in a large sample of children and adolescents in Italy, accounting for age at time of exposure. Methods: 20 016 children (mean age 7 years) and 13 266 adolescents (mean age 13 years) completed questionnaires on indoor exposures and respiratory symptoms/diseases. Statistical analyses were adjusted for sex, age, questionnaire’s compiler, area of residence, season of interview, parental educational status, family history of asthma, rhinitis, eczema, chronic obstructive pulmonary disease, presence of gas water heaters, passive smoking, pets, and active smoking (only for adolescents). Population attributable risk % (PAR) was also computed. Results: Asthma was more strongly related to only early than to only current exposure, both in children (OR 1.80, 95% CI 1.41 to 2.30) and adolescents (OR 1.89, 95% CI 1.38 to 2.59). The same result was found for rhino-conjunctivitis (OR 1.46, 95% CI 1.17 to 1.82), in children, and for wheeze among adolescents (OR 1.56, 95% CI 1.15 to 2.11). In children, wheeze (OR 1.98, 95% CI 1.47 to 2.66) and eczema (OR 1.44, 95% CI 1.09 to 1.91) were more strongly related to mould/dampness when exposed both early and currently; the same occurred in adolescents for rhino-conjunctivitis (1.78, 95% CI 1.30 to 2.45). Although persistent cough/phlegm was significantly related to mould/dampness exposure in children, regardless of exposure timing, no significant association between mould/dampness exposure and eczema or cough/phlegm was found among adolescents. PAR estimates were higher for only early than only current exposures. Avoiding early only exposure would abate wheeze by 6%, asthma or cough/phlegm by 7%, rhino-conjunctivitis in children by 4%, and in adolescents, asthma by 6%, and wheeze by 4%. Conclusions: Respiratory disorders such as wheeze and asthma can often be explained by exposure to home mould/dampness, especially early in life. The association seems more evident in children than in adolescents. These findings may suggest the need for environmental prevention strategies.

Respiratory health and indoor air pollutants based on quantitative exposure assessments

We reviewed the main epidemiological studies that evaluate the respiratory effects of indoor air pollutants quantitatively in industrialised countries. Consistent results support short-term (aggravation) and, although more rarely, long-term (prevalence augmentation) effects on asthma, chronic bronchitis and chronic obstructive pulmonary disease (COPD) in indoor settings with poor air quality. Environmental tobacco smoke is one of the most important risks for respiratory symptoms and diseases worldwide. The evidence is also reliable for indoor nitrogen dioxide and particulate matter, which have been associated with asthma, bronchitis and COPD. Whereas formaldehyde and volatile organic compounds seem to be the main pollutants in indoor settings, relevant papers on their respiratory effects are still scarce, and limited to asthma and bronchitis. Moulds have been associated with an increased risk of asthma and COPD. Contradictory results have been found between endotoxins and asthma. The role of phthalates, persistent organic pollutants and flame retardants in respiratory diseases remains to be established. Results from rural areas of industrialised countries indicate that exposure to some indoor bio-contaminants might be protective in early life, while it is associated with adverse respiratory adverse effects in adulthood. Studies focusing on indoor air pollutants should be developed to better understand their involvement in the inception and aggravation of respiratory diseases.

School air quality related to dry cough, rhinitis and nasal patency in children

Controls for indoor air quality (IAQ) in schools are not usually performed throughout Europe. The aim of this study was to assess the effects of IAQ on respiratory health of schoolchildren living in Norway, Sweden, Denmark, France and Italy. In the cross-sectional European Union-funded HESE (Health Effects of School Environment) Study, particulate matter with a 50% cut-off aerodynamic diameter of 10 µm (PM10) and CO2 levels in a day of normal activity (full classroom) were related to wheezing, dry cough at night and rhinitis in 654 children (10 yrs) and to acoustic rhinometry in 193 children. Schoolchildren exposed to PM10 >50 μg·m−3 and CO2 >1,000 ppm (standards for good IAQ) were 78% and 66%, respectively. All disorders were more prevalent in children from poorly ventilated classrooms. Schoolchildren exposed to CO2 levels >1,000 ppm showed a significantly higher risk for dry cough (OR 2.99, 95% CI 1.65–5.44) and rhinitis (OR 2.07, 95% CI 1.14–3.73). By two-level (child, classroom) hierarchical analyses, CO2 was significantly associated with dry cough (OR 1.06, 95% CI 1.00–1.13 per 100 ppm increment) and rhinitis (OR 1.06, 95% CI 1.00–1.11). Nasal patency was significantly lower in schoolchildren exposed to PM10 >50 μg·m−3 than in those exposed to lower levels. A poor IAQ is frequent in European classrooms; it is related to respiratory disturbances and affects nasal patency.

Wheeze and asthma in children: associations with body mass index, sports, television viewing, and diet.

Background: Obesity, physical activity, and dietary habits are distinct but strongly interrelated lifestyle factors that may be relevant to the prevalence of wheeze and asthma in children. Our goal was to analyze the relationship of body mass index (BMI), regular sports participation, TV viewing, and diet with current wheezing and asthma. Methods: We investigated 20,016 children, aged 6–7 years, who were enrolled in a population-based study. Parents completed standardized questionnaires. Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs), while adjusting for several confounders and simultaneously considering BMI, regular sports activity, TV viewing and selected dietary items. Results: A total of 1575 children (7.9%) reported current wheezing and 1343 (6.7%) reported current asthma. In a multivariate model, an elevated BMI was associated with wheeze and current asthma: children from the highest quintile (compared with the lowest quintile) had an increased risk of wheeze (OR = 1.47; CI = 1.20–1.82) or current asthma (1.61; 1.28–2.01). Wheeze or asthma was not associated with regular sports activity. Subjects who spent 5 or more hours per day watching television were more likely to experience wheeze (1.53; 1.08–2.17) or current asthma (1.51; 1.04–2.2) compared with those who viewed TV less than 1 hour a day. Adding salt to food was strongly and independently associated with current wheeze (2.58; 1.41–4.71) and current asthma (2.68; 1.41–5.09). Conclusions: Our data support the hypothesis that high body weight, spending a lot of time watching television, and a salty diet each independently increase the risk of asthma symptoms in children.

Total viable molds and fungal DNA in classrooms and association with respiratory health and pulmonary function of European schoolchildren.

To cite this article: Simoni M, Cai G‐H, Norback D, Annesi‐Maesano I, Lavaud F, Sigsgaard T, Wieslander G, Nystad W, Canciani M, Viegi G, Sestini P. Total viable molds and fungal DNA in classrooms and association with respiratory health and pulmonary function of European schoolchildren. Pediatr Allergy Immunol 2011: 22: 843–852.

Adverse effects of outdoor pollution in the elderly.

With fewer newborns and people living longer, older people are making up an increasing fraction of the total population. Epidemiological evidence shows that older-age-related health problems affect a wide and expanding proportion of the world population. One of the major epidemiological trends of this century is the rise of chronic diseases that affect more elderly than younger people. A total of 3.7 million premature deaths worldwide in 2012 are attributable to outdoor air pollution; the susceptibility to adverse effects of air pollution is expected to differ widely between people and within the same person, and also over time. Frailty history, a measure of multi-system decline, modifies cumulative associations between air pollution and lung function. Moreover, pre-existing diseases may determine susceptibility. In the elderly, due to comorbidity, exposure to air pollutants may even be fatal. Rapid and not-well-planned urbanization is associated with high level of ambient air pollution, mainly caused by vehicular exhausts. In general, there is sufficient evidence of the adverse effects related to short-term exposure, while fewer studies have addressed the longer-term health effects. Increased pollution exposures have been associated with increased mortality, hospital admissions/emergency-room visits, mainly due to exacerbations of chronic diseases or to respiratory tract infections (e.g., pneumonia). These effects may also be modulated by ambient temperature and many studies show that the elderly are mostly vulnerable to heat waves. The association between heat and mortality in the elderly is well-documented, while less is known regarding the associations with hospital admissions. Chronic exposure to elevated levels of air pollution has been related to the incidence of chronic obstructive pulmonary disease (COPD), chronic bronchitis (CB), asthma, and emphysema. There is also growing evidence suggesting adverse effects on lung function related to long-term exposure to ambient air pollution. Few studies have assessed long-term mortality in the elderly. It is still unclear what are the pollutants most damaging to the health of the elderly. It seems that elderly subjects are more vulnerable to particulate matter (PM) than to other pollutants, with particular effect on daily cardio-respiratory mortality and acute hospital admissions. Not many studies have targeted elderly people specifically, as well as specific respiratory morbidity. Most data have shown higher risks in the elderly compared to the rest of the population. Future epidemiological cohort studies need to keep investigating the health effects of air pollutants (mainly cardiopulmonary diseases) on the elderly.

Indoor exposures and acute respiratory effects in two general population samples from a rural and an urban area in Italy.

A study of indoor air exposures and acute respiratory effects in adults was conducted in the Po Delta (rural) and Pisa (urban) areas of Italy. Indoor exposures were monitored for nitrogen dioxide (NO2) and particulate matter <2.5 μm (PM2.5) for 1 week during the winter or summer in a total of 421 houses (2/3 in Pisa). Information on house characteristics, subjects’ daily activity pattern and presence of acute respiratory symptoms was collected by a standardized questionnaire. Peak expiratory flow (PEF) maneuvers were performed by adult subjects four times daily; maximum amplitude and diurnal variation were taken into account. Indices of NO2 and PM2.5 exposures were computed as the product of weekly mean pollutant concentration by the time of daily exposure. Mean levels of pollutants were significantly higher in winter than in summer, regardless of the area. The relationship between exposure indices and acute respiratory symptoms was investigated only in winter. In spite of a slightly lower indoor level in the urban than in the rural area in winter (NO2: 15 vs. 22 ppb; PM2.5: 67 vs. 76 μg/m3), prevalence rates of acute respiratory symptoms were significantly higher in the urban than in the rural area. Acute respiratory illnesses with fever were significantly associated with indices of NO2 (odds ratio (OR)=1.66; 95% CI=1.08−2.57) and PM2.5 exposures (OR=1.62; 95% CI=1.04−2.51), while bronchitic/asthmatic symptoms were associated only with PM2.5 (OR=1.39; 95% CI=1.17−1.66). PEF variability was positively related only to PM2.5 exposure index (OR=1.38; 95% CI=1.24−1.54, for maximum amplitude; OR=1.37; 95% CI=1.23−1.53, for diurnal variation). In conclusion, indoor pollution exposures were associated with the presence of acute respiratory symptoms and mild lung function impairment in a rural and an urban area of Northern-Central Italy.

Indoor air pollution and respiratory health in the elderly

Data on respiratory effects of indoor air pollution in elderly are scanty. The purpose of this review is to summarize current knowledge on adverse respiratory effects of indoor air pollution in individuals aged over 65 years, by presenting existing epidemiological evidence. Using MEDLINE database through PubMed, we identified relevant publications published between 1991 and 2011 in English on respiratory health effects of indoor air pollution in elderly (>65 years). A total of 61 studies were found and after application of the inclusion criteria: (i) epidemiologic studies published in English in peer-reviewed journals between January 1991 and December 2011, (ii) study population with age over or equal 65 years, and (iii) outcome of respiratory symptoms and disease with the exclusion of lung cancer, 33 relevant publications were selected. Most of them showed significant relationships between exposure to major indoor air pollutants and various short-term and long-term respiratory health outcomes such as wheezing, breathlessness, cough, phlegm, asthma, COPD, lung cancer and more rarely lung function decline. The most consistent relationship is found between chronic obstructive pulmonary disease (COPD) and environmental tobacco smoke (ETS). Further studies in the elderly population are needed in order to define causal relationships between exposures to indoor air pollution and underlying mechanisms in this sub-population.

Effects of pet exposure in the first year of life on respiratory and allergic symptoms in 7-yr-old children. The SIDRIA-2 study

Lombardi E, Simoni M, La Grutta S, Viegi G, Bisanti L, Chellini E, Dell’Orco V, Migliore E, Petronio MG, Pistelli R, Rusconi F, Sestini P, Forastiere F, Galassi C and the SIDRIA‐2 Collaborative Group. Effects of pet exposure in the first year of life on respiratory and allergic symptoms in 7‐yr‐old children. The SIDRIA‐2 study. 
Pediatr Allergy Immunol 2010: 21: 268–276.
© 2009 John Wiley & Sons A/S