Table 6—

Association between general respiratory symptoms, work-related symptoms, atopy and bronchial hyperresponsiveness (BHR) and trichloramine levels combined with the working quantity, adjusted for age, smoking and sex#

Cumulative chloramine
General respiratory symptoms
 Problems with breathing?1.1 (0.9–1.4)
  Yes, constantly1.2 (0.8–1.9)
  Frequently, but it always improves1.2 (0.8–1.7)
  Very rarely1.0 (0.7–1.3)
 Cough during last 12 months1.2 (>1.0–1.4)*
 Phlegm during last 12 months1.1 (0.8–1.4)
 Tightness of chest during last 12 months1.4 (1.2–1.6)*
 Dyspnoea when walking on a flat surface with people of the same age1.1 (0.8–1.5)
 Wheeze during last 12 months0.9 (0.7–1.2)
 Wheeze and shortness of breath during last 12 months0.9 (0.6–1.2)
 Have you ever had asthma?0.9 (0.7–1.3)
 Was it doctor diagnosed?0.9 (0.6–1.3)
 Asthma attacks during last 12 months0.9 (0.5–1.5)
 Woken up by shortness of breath during last 12 months1.0 (0.8–1.4)
 Shortness of breath after exercise during last 12 months1.1 (0.8–1.4)
 Asthma attacks during last 12 months whilst at work1.3 (0.9–1.9)
 Have you ever changed work because of asthma?NR
 Asthma medication during last 12 months1.0 (0.7–1.6)
Asthma-related symptoms
 Cough1.4 (1.2–1.6)*
 Phlegm1.1 (0.9–1.4)
 Wheeze0.9 (0.6–1.3)
 Wheeze and shortness of breath0.9 (0.6–1.4)
 Shortness of breath0.9 (0.7–1.1)
 Tightness1.1 (0.8–1.4)
Upper respiratory symptoms
 Hoarseness1.6 (1.2–2.1)*
 Lost voice1.5 (1.1–2.0)*
 Sinusitis1.4 (>1.0–1.8)*
 Chronic cold1.3 (1.0–1.8)
 Dry/sore throat1.2 (1.0–1.6)
 Blocked nose1.1 (0.9–1.4)
 Runny nose1.1 (0.9–1.4)
 Sneezing1.3 (1.1–1.6)*
 Itchy, watery eyes0.9 (0.7–1.1)
BHR1.0 (0.8–1.4)
Atopy1.4 (1.1–1.8)*
  • Data are presented as odds ratio (95% confidence interval). NR: no results available due to low numbers of individuals with symptoms. #: odds ratios were calculated using an interquartile range of 15.06 mg·m−3. This value was based on the cumulative chloramine levels, obtained by multiplying the calculated chloramine level of each pool by the quantity of hours working per week. : work-related symptoms. *: p<0.05.