Table 2.

Serum organochlorine pesticide levels in Costa Rica in 2012 (n=89) and NHANES in 2003–2004 (n=1888).

Pesticide (ng/ml)	Costa Rica*				NHANES age>50**
	<LOD (%)***	25%	50%	75%	<LOD (%)****	25%	50%	75%
β-HCH	0	0.59	0.71	0.87	31	0.06	0.12	0.21
Dieldrin	47	0.07	1.63	4.87	10	0.04	0.06	0.09
p,p′–DDT	25	0.09	0.13	0.18	18	0.04	0.06	0.11
p,p′–DDE	7	0.27	0.67	1.25	0	2.32	5.10	10.12

^*Average age 76 in 2012.

^**1888, 1859, 1978, and 1300 NHANES samples in 2003–2004 for β-HCH, p,p′–DDT, p,p′–DDE, and dieldrin, respectively. Average age 67 in 2003–2004.

^***LODs in Costa Rican samples for β-HCH, p,p′–DDT and p,p′–DDE, and dieldrin were 0.10, 0.05, and 0.05, and 0.25 ng/ml, respectively. Values below LOD imputed assuming a log normal distribution, in order to calculate percentiles. Higher percentage of values below LOD for dieldrin in Costa Rica vs. NHANES results from higher LOD in Costa Rica analyses.

^****LOD in NHANES varied by batches, but were approximately 0.09, 0.02, 0.02, and 0.02 for β-HCH, DDT, DDE, and dieldrin, respectively. No samples for DDE in NHANES were below the LOD. Samples below LOD were divided by the square root of 2 for calculating percentiles.