# Table 1 Equations for regression lines and confidence ranges

Survey X Y Typea Equation
The 1991–1997 survey (n = 30)
Cd-B Cd-D 95 % UL $${\text{Y}} = + 10.18 + 7.19{\text{X}} + 1.772{\text{X}}^{2}$$   Eq. 1
(μg/l) (μg/day) RL $${\text{Y}} = - 1.13 + 14.36{\text{X}}$$ r = 0.76b Eq. 2
95 %LL $${\text{Y}} = - 12.43 + 21.54{\text{X}} - 1.772{\text{X}}^{2}$$   Eq. 3
Cd-Ucr Cd-D 95 % UL $${\text{Y}} = + 12.84 + 3.33{\text{X}} + 0.169{\text{X}}^{2}$$   Eq. 4
(μg/g cr) (μg/day) RL $${\text{Y}} = + 5.35 + 4.90{\text{X}}$$ r = 0.79b Eq. 5
95 %LL $${\text{Y}} = - 2.13 + 6.48{\text{X}} - 0.169{\text{X}}^{2}$$   Eq. 6
The 1977–1981 survey (n = 18)
Cd-B Cd-D 95 % UL $${\text{Y}} = + 33.88 - 6.45{\text{X}} + 3.214{\text{X}}^{2}$$
(μg/l) (μg/day) RL $${\text{Y}} = - 20. 3 2+ 1 7. 5 2 {\text{X}}$$ r = 0.68c
95 %LL $${\text{Y}} = - 74.53 + 41.49{\text{X}} - 3.214{\text{X}}^{2}$$
1. aThe equations are regression line (RL) and 95 %upper (95 % UL) or lower limit (95 % LL)
2. b p < 0.001 for both cases
3. c p < 0.01