Appendix 4 Exposure and respiratory outcomes

Australian studies on associations between exposure to NO2, ETS, formaldehyde and VOC and respiratory outcomes including asthma

Abbreviations & Glossary

FEV₁ = Forced Expiratory Volume in 1 second
FVC = Forced Vital Capacity
NS = Not significant (p>0.05)
OR = Odds ratio

Authors	City/Years	Study	Exposures	Confounders		Outcome	Findings
Garrett et al 1998¹	Latrobe Valley, Victoria 1989	Longitudinal: 80 households with 148 children (53 asthmatics and 95 non-asthmatics); over a year	Indoor NO₂ levels	Controlled: parental asthma, parental allergy, child age, passive smoking and socio-economic status measured by house ownership		Respiratory symptoms	Nitrogen dioxide concentrations in the study houses were low, with a total of 10 samples exceeding 60 ppb (115 µg/m3). The overall median level was 11.6 micrograms/m3 (6.0 ppb), ranging from < 0.7 to 246 micrograms/m3 (128 ppb). Major indoor nitrogen dioxide sources were: gas stoves, vented gas heaters, and smoking. Some 67% of variation in indoor nitrogen dioxide levels could be explained by presence of major sources, house age, and outdoor levels. Gas stoves were the main contributors. The presence of a gas stove significantly increased the likelihood of respiratory symptoms (odds ratio 2.2 [1.0-4.8]). However, neither of the other major nitrogen dioxide sources, gas heaters or smoking, were found to be significantly associated with respiratory symptoms. Nitrogen dioxide exposure was a marginal risk factor for respiratory symptoms. The interaction between atopy and gas stoves or NO2 exposure was NS.

Pilotto et al 1997²	ACT	Longitudinal: 388 children aged 6-11 years; conducted in winter	Indoor NO₂ levels	Controlled ???		Respiratory symptoms	Exposure to NO2 at hourly peak levels of the order of > or = 80 ppb, compared with background levels of 20 ppb, was associated with a significant increase in sore throat, colds and absences from school.

Smith et al 2000³	Adelaide	A longitudinal study over 6 weeks Self-reported asthma (n=125)	Participants wore lapel badges that measured NO2 daily	Controlled for other exposures		Respiratory symptoms	A significant interaction between NO2 and age was observed. In adults, exposure to NO2 was associated with cough with a 1 day lag (OR: 1.15, 95% CI: 1.01-1.31). Daily personal exposures to NO2 are associated with asthmatic symptoms in children.

Volkmer et al 1995⁴	South Australia	Cross sectional study 14,124 families with a child aged 4 years 3 months to 5 years. (represents 73% of the targeted State preschool population.)	parental smoking, type of fuel used for cooking and heating and method used for home cooling		Controlled for other exposures, geographic location and SES	Respiratory health	Natural gas stove compared to an electric stove was significantly associated with increased prevalence rates for: (i) asthma (odds ratio [OR] 1.24); (ii) wheezing in the preceding 12 months (OR 1.16); excessive colds (OR 1.14); and hay fever (OR 1.13). The use of a unflued gas heater compared to other forms of heating was significantly associated with increased prevalence rates for dry cough (OR 1.26), ever having wheezed (OR 1.15) and wheezing in the preceding 12 months (OR 1.18). The use of a wood fire/heater compared to other forms of heating was significantly associated with a reduced prevalence rate for dry cough (OR 0.84) and ever having wheezed (OR 0.82). Parental smoking was significantly associated with increased prevalence rates for bronchitis (OR 1.21) and ever having wheezed (OR 1.24).

Lewis et al 1998⁵	Hunter and Illawarra regions of New South Wales	A cross-sectional survey: 1993 3023 children aged 8 to 10 years.	Out door pollutants, passive smoking at home, gas heaters.		Controlled for other exposures	Respiratory symptoms	gas heating was associated with frequent wheeze. Presence of an adult smoker in the home was associated with chest colds

Reese et al⁶	WA	Cross sectional study: 468 children (48 with bronchioloitis)	Cotinine levels		Controlled for confounders???	Bronchioloits	Cotinine levels were higher in the group with bronhiolitis compared to children with non respiratory illness. Cotinine levels were correlated with parents’ current smoking

Habby et al 1994⁷	from two rural regions of NSW	Cross sectional study: 2765 children	Parental smoking		Controlled for confounders ???	Respiratory illness, lung function, BHR	Passive smoking was associated with reduced FEV1, PEFR, and FEF25-75%.

Garrett et al 1998¹	Latrobe Valley, Victoria 1989	Longitudinal: 80 households with 148 children (53 asthmatics and 95 non-asthmatics); over a year	Formaldehyde levels: in homes	Controlled: parental asthma, parental allergy, child age, passive smoking and socio-economic status measured by house ownership		Atopy and Respiratory symptoms	The median indoor formaldehyde level was 15.8 microg/ m3 (12.6ppb), with a maximum of 139 microg/m3 (111 ppb). Formaldehyde exposure was associated with atopy (OR=1.40 (0.98-2.00, 95% CI) with an increase in bedroom formaldehyde levels of 10 microg/m3). Furthermore, more severe allergic sensitization was demonstrated with increasing formaldehyde exposure. On the other hand, there was no significant increase in the adjusted risk of asthma or respiratory symptoms with formaldehyde exposure. However, among children suffering from respiratory symptoms, more frequent symptoms were noted in those exposed to higher formaldehyde

Franklin et al 2000⁸	Perth, Year?	Cross sectional: 224 healthy children 6 to 13 yr of age	Formaldehyde: in homes	Controlled: atopy and other variables		Lung function Exhaled NO	There was no effect of formaldehyde levels on FVC or FEV1. There was, however, significantly higher levels of NO2 measured from children living in homes with average formaldehyde levels greater than 50 ppb (p = 0.02). Exhaled NO levels were 15.5 ppb (10.5 to 22.9 ppb) for children from homes with formaldehyde concentrations 50 ppb and 8.7 ppb (7.9 to 9.6 ppb) for children from homes with formaldehyde concentrations < 50 ppb

Beach et al 1997⁹	Melbourne	Double blind cross over study; 17 asthmatics; VOC free paint Vs conventional paint	VOC in paint	Controlled for with in variation		Respiratory symptoms, lung function airway responsiveness	The new paint appears to be less likely to cause a worsening of respiratory symptoms than conventional acrylic paint, although this difference is not reflected in measurements of lung function or airway responsiveness.

References

1	Garrett, M.H., et al., Respiratory Symptoms in Children and Indoor Exposure to Nitrogen Dioxide and Gas Stoves. Am. J. Respir. Crit. Care Med., 1998. 158(3): p. 891-895.
2	Pilotto, L.S., et al., Respiratory effects associated with indoor nitrogen dioxide exposure in children. International Journal of Epidemiology., 1997. 26(4): p. 788-96.
3	Smith, B.J., et al., Health effects of daily indoor nitrogen dioxide exposure in people with asthma. Eur Respir J. 2000. 16(5): p. 879-85.
4	Volkmer, R.E., et al., The prevalence of respiratory symptoms in South Australian preschool children. II. Factors associated with indoor air quality. JPCH, 1995. 31(2): p. 116-20.
5	Lewis, P.R., et al., Outdoor air pollution and children's respiratory symptoms in the steel cities of New South Wales. MJA, 1998. 169: p. 459-463.
6	Reese, A.C., et al., Relationship between urinary cotinine level and diagnosis in children admitted to hospital. American Review of Respiratory Disease., 1992. 146(1): p. 66-70.
7	Haby, M.M., J.K. Peat, and A.J. Woolcock, Effect of passive smoking, asthma, and respiratory infection on lung function in Australian children. Pediatric Pulmonology., 1994. 18(5): p. 323-9.
8	Franklin, P., P. Dingle, and S. Stick, Raised Exhaled Nitric Oxide in Healthy Children Is Associated with Domestic Formaldehyde Levels. Am. J. Respir. Crit. Care Med., 2000. 161(5): p. 1757-1759.
9	Beach, J.R., et al., The effects on asthmatics of exposure to a conventional water-based and a volatile organic compound-free paint. Eur Respir J, 1997. 10(3): p. 563-6.

Appendix 4 Exposure and respiratory outcomes

Abbreviations & Glossary

Authors

City/Years

Study

Exposures

Confounders

Outcome

Findings

References