Int. J. Environ. Res. Public Health 2009, 6 2402 Figure 1. Changes in water-extractable metal concentrations in composted household (CHHW-U;CHHW-T), municipal (CMSW-U; CMSW-T) and agricultural (CMSW-U; CMSW-T) solid wastes via unturned (-U) and turned (-T) production procedures in relation to temperature variation. 0 20 40 60 80 100 Temperature (oC) 0 20 80 100 40 60 Temperature (oC) 0.22 )g 0.2 /gK0.18 (m0.16 ion0.14 llftscbuoea0000...001.1862 r - r te0.04 aW0.02 0 0.18 )g 0.16 /gK 0.14 (m0.12 itcno 0.1 fra 0.08 lbe 0.06 u lso 0.04 - tre 0.02 aW 0 -0.02 0 )g0.14 /gK0.12 (nm0.1 o i tca0.08 r le0.06 f b lou0.04 s - te0.02 r aW 0 Zn Pb Cu Cd CHHW-U Zn Pb Cu Cd CMSW-U 50 Temperature (oC) 100 Zn Pb Cu Cd CAGW-U 0 20 80 100 40 60 Temperature (oC) 0.16 )g0.14 K /(gm0.12 ion 0.1 t c fra0.08 llub0.06 e o r-s0.04 e taW0.02 0 0.18 )0.16 /K0.14 g (m0.12 g ion 0.1 t rca0.08 f le0.06 b lou0.04 s r-e0.02 taW 0 -0.02 0 ) 0.16 /kg 0.14 g (m0.12 itcnoa 0.00.81 r lfe 0.06 lub 0.04 -s o 0.02 trea 0 W-0.02 0 Zn Pb Cu Cd Zn Pb Cu Cd CHHW-T CMSW-T Zn 20 50 Temperature (oC) 100 Pb CAGW-T Cu Cd 40 60 Temperature (oC) 80 100 Table 2. Linear regression models and correlation coefficients for water-extractable metal concentrations in composted organic wastes versus temperature. Compost type Metal type CHHW-U CHHW-T CMSW-U Cd Cu Pb Zn Cd Cu Pb Zn Cd Cu Pb Zn Linear regression equation (Y = bx + c) Y = 0.001x – 0.0014 Y = 0.0009x – 0.00084 Y = 0.003x + 0.0497 Y = -0.0003x + 0.0963 Y = 0.001x – 0.0020 Y = 0.0007x + 0.0015 Y = 0.0002x + 0.0679 Y = -0.0005x + 0.091 Y = 4E-05x + 0.0011 Y = 0.0006x + 0.0031 Y = -0.0007x + 0.0905 Y = -0.0009x + 0.099 R2 0.4699 0.7756 0.0565 0.0159 0.6031 0.5661 0.0187 0.0785 0.6687 0.4707 0.2012 0.1981 r 0.685* 0.881*** 0.238 0.126 0.777** 0.752* 0.137 0.280 0.818** 0.686* 0.449 0.445