Table 4.

Age- and gender-adjusted odds ratios and 95% CIs for six respiratory symptoms according to four categories of in utero arsenic exposure, with those who were never exposed in utero and throughout childhood up to the present as the referent group

	10-199 µg/l	200-399 µg/l	400-599 µg/l	600+ µg/l
Respiratory symptoms	OR (95% CI)	OR (95% CI)	OR (95% CI)	OR (95% CI)	P-trenda
Wheezing ever	1.98 (1.03–3.80)	1.51 (0.83–2.74)	3.17 (1.78–5.64)	2.12 (1.19–3.76)	<0.001
Asthma	1.23 (0.50–3.02)	1.88 (0.90–3.92)	2.26 (1.13–4.49)	2.38 (1.17–4.83)	<0.01
Coughing when not having a cold (last 12 months)	2.37 (0.92–6.09)	1.62 (0.64–4.11)	1.78 (0.74–4.31)	2.47 (1.05–5.79)	0.03
Shortness of breath when walking fast or climbing	1.07 (0.27–4.28)	2.89 (1.06–7.91)	4.09 (1.56–10.7)	3.20 (1.18–8.71)	<0.01
Shortness of breath when walking on level ground	1.30 (0.72–7.58)	2.21 (0.54–9.12)	4.50 (1.17–17.3)	3.37 (0.88–12.8)	0.01
Wheezing when not having a cold	5.01 (0.78–32.0)	1.57 (0.20–12.1)	8.65 (1.64–45.7)	8.21 (1.56–43.1)	<0.01

^aOne-sided.