Table 4.

The association between variation in element concentration and individual-level and community-level variables in Hainan Province, China (2008).

		As		Cd		Pb		Se		Zn		Cu
		Coef.	p-value	Coef.	p-value	Coef.	p-value	Coef.	p-value	Coef.	p-value	Coef.	p-value
Fixed effect (Individual level)
Age		0.004	< 0.001	0.006	< 0.001	0.002	0.068	< 0.001	0.554	0.003	0.004	0.002	0.032
Sex (ref = Male)	Female	0.064	0.018	0.107	< 0.001	0.007	0.769	0.064	0.001	−0.062	0.017	0.039	0.110
BMI		−0.002	0.714	−0.013	0.002	−0.005	0.239	0.003	0.299	−0.004	0.323	−0.007	0.094
Education a	9 years	0.051	0.149	−0.047	0.127	−0.007	0.828	−0.025	0.285	0.030	0.379	−0.027	0.390
(ref < 9 years)	> 9 years	0.004	0.867	0.015	0.462	0.013	0.553	−0.003	0.875	0.028	0.225	−0.010	0.637
Involvement in the market economy b		0.018	0.495	0.032	0.158	0.050	0.031	0.054	0.003	0.040	0.117	0.024	0.317
Fixed effect (Community level)
Community-level development c		0.023	0.561	0.067	0.025	0.027	0.516	0.049	0.131	−0.036	0.539	−0.001	0.985
Ethnicity (ref = Han)		0.267	0.109	0.072	0.140	−0.086	0.479	−0.102	0.212	0.030	0.854	−0.052	0.715
Random effect		Var.		Var.		Var.		Var.		Var.		Var.
Individual level		0.079		0.061		0.060		0.035		0.072		0.063
Community level		0.009		< 0.001		0.010		0.003		0.021		0.016
Intra-class correlation (%)		10.5		0.4		14.5		7.9		22.5		20.4

^a Educational attainment was categorized into three groups: <9, 9, and >9 years of schooling; ^b Information on respondents’ involvement in the market economy was evaluated by asking about agrochemical use in the previous year, which was dichotomized as: yes or no; ^c The degree of community-level economic development was based on the proportion of those who live in better housing, which resulted in the following ordering: HC (least economically developed = 1), HP, HY, HT, and HS (most economically developed = 5).