Respiratory morbidity and medical visits associated with dampness and air-conditioning in offices and homes

Household environmental factors and children's respiratory health: comparison of two cross-sectional studies over 25 years in Wuhan, China

Background

Over the recent decades, residential lifestyle and household environment have changed substantially with rapid development of industrialization and urbanization in China. Whether the prevalence of respiratory diseases changed is still lack of evidence. The objective of this study is to assess potential changes in children’s respiratory disease prevalence and associated household environmental factors in Wuhan over a 25-year time interval.

Methods

Two cross-sectional studies in the Period 1 (1993 to 1996) and Period 2 (2017 to 2018) were compared in this research. Elementary school children in period 1 (N=2,517) and in period 2 (N=3,152) were recruited in Wuhan, China. The respiratory health condition, home environmental factors, and family socioeconomic status of each subject were acquired through questionnaire survey using the same protocols in both periods. We used the Chi-square test to analyze the difference of household environmental factors (focused on three indoor air quality determinants) and children’s respiratory health condition between two periods. Logistic regression models were used to assess the impacts of household environmental determinants on children’s respiratory diseases and symptoms between the two studies, by adjusting a set of covariates.

Results

The three indoor air quality determinants have reduced substantially in prevalence from period 1 to period 2: environment tobacco smoke (ETS) from 86.6% to 45.9%, household coal use from 47.6% to 4.9%, and kitchen smoke from 58.9% to 7.3%. The prevalence of certain respiratory symptoms in children significantly decreased, such as cough with colds (51.1% to 41.6%) and phlegm with colds (22.3% to 17.7%). The prevalence of asthma was 2.5% and 2.4% and that of bronchitis was 27.1% and 29.8% in both periods. Coal use was a risk factor for asthma in period 1 (OR =2.34, 95% CI: 1.30–4.23), while it was not significantly associated with prevalence of asthma in period 2 (OR =0.60, 95% CI: 0.08–4.51).

Conclusions

Household indoor air quality determinants and respiratory health condition of children in Wuhan has been improved over the last 25 years. At present, kitchen smoke is an important factor affecting the prevalence of wheeze whatever child has a cold or not and reducing exposure to ETS could be beneficial to protect children to be less likely to develop bronchitis.

Self-reported mould and long-term sickness absences from work

Aims: The impact of indoor mould on employees’ long-term absence from sickness (more than 10 days of absence) is poorly understood. This paper examines whether self-reported mould was related to long-term absences from work between 1 and 3 years later. Methods: By using negative binomial modelling, we analysed a representative sample of the working-age population in Finland (N = 16,084) from the Finnish Quality of Work Life Surveys in 1997, 2003, 2008 and 2013 combined with the register-based follow-up data of participants’ long-term sickness absences covering a period of 1 to 3 years after the Finnish Quality of Work Life Surveys was collected. Results: After all necessary background, work- and health-related factors were included in the model, employees who reported mould in their work had 1.20 higher rates of long-term sickness absence than those who did not report mould (mould: estimated marginal mean = 13.45 days; no mould: estimated marginal mean = 11.23). If employees perceived that mould caused strain, they had 1.30 higher rates of long-term absence than those who did not report such strain (mould caused strain: estimated marginal mean = 14.64 days; mould did not cause strain: estimated marginal mean = 11.25). In total, 10% (N=1628) of employees reported mould in their workplace and 6% (N=987) reported that mould caused strain. Conclusions: Supervisors, occupational physicians and other authorities need to take employees’ complaints of mould in the workplace seriously.

The Combined Effect of Poor Perceived Indoor Environmental Quality and Psychosocial Stressors on Long-Term Sickness Absence in the Workplace: A Follow-Up Study

Background: Poor perceived indoor environmental quality (IEQ) can generate conflicts and experiences of injustice in workplaces. Therefore we examined whether the combined effect of poor IEQ and self-reported psychosocial stressors (low social support from supervisors and experiences of injustice) increase the risk of employees’ long-term sickness absence (more than 10 days) in comparison to employees who report only poor perceived IEQ and no psychosocial stressors. Methods: Using negative binomial modelling, we analysed a representative sample of the working-age population in Finland (N = 16,084) from the Finnish Quality of Work Life Surveys (FQWLS) from 1997, 2003, 2008 and 2013, combined with register-based follow-up data on employees’ long-term absences covering a period of one to three years after each FQWLS was collected. Results: After background variables were included in the model, employees who reported poor IEQ and low social support had 1.18 (incidents rate ratios; 95% CI 1.05–1.33) higher rates of long-term absence than those who reported poor IEQ and high support. Similarly, employees who reported poor IEQ and experiences of injustice had 1.31(incidents rate ratios; 95% CI 1.15–1.48) higher rates of absence than those who reported poor IEQ and no injustice. Conclusions: Employees who reported poor perceived IEQ and a psychosocial stressor had higher rates of long-term sickness absence one to three years later, in comparison with those who report only poor perceived IEQ and no psychosocial stressors. These findings demonstrate the importance of taking account of psychosocial stressors as well, when resolving indoor environmental problems.

Towards establishing evidence-based guidelines on maximum indoor temperatures during hot weather in temperate continental climates

Rising environmental temperatures represent a major threat to human health. The activation of heat advisories using evidence-based thresholds for high-risk outdoor ambient temperatures have been shown to be an effective strategy to save lives during hot weather. However, although the relationship between weather and human health has been widely defined by outdoor temperature, corresponding increases in indoor temperature during heat events can also be harmful to health especially in vulnerable populations. In this review, we discuss our current understanding of the relationship between outdoor temperature and human health and examine how human health can also be adversely influenced by high indoor temperatures during heat events. Our assessment of the existing literature revealed a high degree of variability in what can be considered an acceptable indoor temperature because there are differences in how different groups of people may respond physiologically and behaviorally to the same living environment. Finally, we demonstrate that both non-physiological (e.g., geographical location, urban density, building design) and physiological (e.g., sex, age, fitness, state of health) factors must be considered when defining an indoor temperature threshold for preserving human health in a warming global climate.

Benefits and costs of improved IEQ in U.S. offices

This study estimates some of the benefits and costs of implementing scenarios that improve indoor environmental quality (IEQ) in the stock of U.S. office buildings. The scenarios include increasing ventilation rates when they are below 10 or 15 l/s per person, adding outdoor air economizers and controls when absent, eliminating winter indoor temperatures >23°C, and reducing dampness and mold problems. The estimated benefits of the scenarios analyzed are substantial in magnitude, including increased work performance, reduced Sick Building Syndrome symptoms, reduced absence, and improved thermal comfort for millions of office workers. The combined potential annual economic benefit of a set of nonoverlapping scenarios is approximately $20 billion. While the quantitative estimates have a high uncertainty, the opportunity for substantial benefits is clear. Some IEQ improvement measures will save energy while improving health or productivity, and implementing these measures should be the highest priority.

PRACTICAL IMPLICATIONS

Owners, designers, and operators of office buildings have an opportunity to improve IEQ, health, work performance, and comfort of building occupants and to obtain economic benefits by improving IEQ. These benefits can be achieved with simultaneous energy savings or with only small increases in energy costs.

Traditional mould analysis compared to a DNA-based method of mould analysis

Traditional environmental mould analysis is based on microscopic observations and counting of mould structures collected from the air on a sticky surface or culturing of moulds on growth media for identification and quantification. These approaches have significant limitations. A DNA-based method of mould analysis called mould specific quantitative PCR (MSQPCR) was created for more than 100 moulds. Based on a national sampling and analysis by MSQPCR of dust in US homes, a scale for comparing the mould burden in homes was created called the Environmental Relative Mouldiness Index (ERMI).

Effect of cold temperatures on mortality in Cantabria (Northern Spain): a case-crossover study

OBJECTIVES

To determine the impact of low temperatures on mortality in a Spanish region that includes both rural and urban areas.

STUDY DESIGN

Case-crossover study.

METHODS

A case-crossover study was conducted on the impact of cold temperatures on mortality in Cantabria, a Spanish region which includes both rural and urban areas, in 2004-2005. Odds ratios for several cold weather indicators were estimated using conditional logistic regression, adjusting for humidity and wind speed. Zero- to 6-day lags in the temperature effect were considered.

RESULTS

Temperatures lower than the 5th percentile were strongly associated with mortality compared with temperatures above the 5th percentile (OR 3.40, 95% confidence interval 2.95-3.93 for 6-day lag). All temperature indices show a negative association with mortality; for instance, the maximum temperature had ORs of 0.71, 0.58, 0.32 and 0.16 for Quintiles 2-5 (reference: Quintile 1). This effect was common to all age groups.

CONCLUSION

Cold weather is strongly associated with mortality in small cities and rural areas.

[Non allergic disorders associated with domestic moulds]

INTRODUCTION

Mouldy surfaces are encountered in up to 20 % of dwellings. Because this indoor air contamination is so widespread, respiratory physicians should be aware of its effects on health and especially of its impact on respiratory diseases.

BACKGROUND

The air contaminants within mouldy dwellings are very diverse. Therefore, a given heath effect cannot be attributed specifically to an individual contaminant. In the field of respiratory diseases, excluding asthma and allergy, long-term exposure to indoor moulds has been recognized as a risk factor for both ENT and bronchial symptoms. Hydrophilic moulds seem to have a larger health impact than other mould species. Among respiratory diseases, inhalation fever and, to a lesser extent, childhood respiratory infections are linked to exposure to moulds. In contrast, the relationship between exposure to indoor moulds and diseases such as sinusitis, mucous irritation syndrome, recurrent respiratory infections in adults, COPD and pulmonary haemorrhage has not been clearly established.

VIEWPOINT

There are still many scientific uncertainties in this field. However, the authorities are becoming more active in dealing with unhealthy buildings and encouraging research.

CONCLUSION

The health impact of mouldy dwellings represents a major public health issue. It needs incentives from institutions and financial support as well as the involvement of many specialists.