Nondietary ingestion of pesticides by children in an agricultural community on the US/Mexico border: Preliminary results

Abstract

An environmental measurement and correlation study of nondietary ingestion of pesticides was carried out in a colonia in south Texas. The purpose of the study was to evaluate young children's exposure to environmental levels of organophosphate ( OP ) pesticides in the household. Samples were collected to measure levels of OP pesticides in housedust and on children's hands. These, in turn, were compared to levels of OP pesticide metabolites in urine. A total of 52 children, 25 boys and 27 girls, participated in the spring and summer of 2000. The children were 7 -53 months of age at the time of recruitment. Univariate and multivariate regression analyses were carried out using SAS statistical software. Seventy -six percent of housedust samples and 50% of hand rinse samples contained OP pesticides. All urine samples had at least one metabolite and over 95% had at least two metabolites above the limit of detection ( LOD ). Total OP loadings in the housedust ranged from nondetectable ( nd ) to 78.03 nmol / 100 cm 2 ( mean = 0.15 nmol / 100 cm 2 ; median = 0.07 nmol / 100 cm 2 ); total OP loadings on the children's hands ranged from nd to 13.40 nmol / 100 cm 2 ( mean = 1.21 nmol / 100 cm 2 ; median = 1.41 nmol / 100 cm 2 ), and creatinine corrected urinary levels ( nmol / mol creatinine ) of total OP metabolites ranged from 3.2 to 257 nmol / mol creatinine ( mean = 42.6; median 27.4 nmol / mol creatinine ). Urinary metabolites were inversely associated with the age of the child ( in months ) with the parameter estimate ( pe ) = À 2.11, P= 0.0070, and 95% confidence interval À 3.60 to À 0.61. The multivariate analysis observed a weak association between concentrations of OP pesticides in housedust, loadings in housedust, and concentration on hands, hand surface area, and urinary levels of OP metabolites. However, hand loadings of OP pesticides were more strongly associated ( r 2 = 0.28; P= 0.0156 ) with urinary levels of OP metabolites ( pe = 6.39; 95% CI 0.98 -11.80 ). This study's preliminary findings suggest that surface loadings of pesticides, on hands, are more highly correlated with urinary bioassays and, therefore, may be more useful for estimation of exposure in epidemiologic studies than levels of pesticides in housedust.

Multimedia measurements and activity patterns in an observational pilot study of nine young children

“…Although recent research efforts have collected much needed data to improve our understanding of the potential exposures of young children in their homes, child care centers, and other environments (Zartarian et al, 1995(Zartarian et al, , 1997(Zartarian et al, , 1998Bradman et al, 1997Bradman et al, , 2007Byrne et al, 1998;Gurunathan et al, 1998;Landrigan et al, 1999;Adgate et al, 2000Adgate et al, , 2001Fenske et al, 2000bFenske et al, , 2002Freeman et al, 2001;Lu et al, 2001;MacIntosh et al, 2001;Pang et al, 2002;Clayton et al, 2003;Curl et al, 2003;Duggan et al, 2003;Shalat et al, 2003;Wilson et al, 2003Wilson et al, , 2004Hore et al, 2005;Morgan et al, 2005;Perera et al, 2006), it is not clear what factors most influence a child's potential exposure to pesticides.…”

Trace elements in scalp hair from potentially exposed individuals in the vicinity of the Bayan Obo mine in Baotou, China

“…A previous study reported that females seemed to have a higher risk of toxic metal exposure than males (Berglund et al, 2011), which is consistent with the finding of the present study. Furthermore, this issue also contradicts the common belief that males are more exposed to these elements than females because they spend more time outside and therefore are more exposed to trace elements from soil and dust (Freeman et al, 2004;Shalat et al, 2003). The gender difference of element contents in hair might be explained on the basis of the exposure frequencies, but the metabolism and physiological roles of elements in the two genders are also of great concern (Vahter et al, 2007).…”

Urine-sampling methods for environmental chemicals in infants and young children

“…This insert is typically used for children who are very young and/or who find it difficult to urinate directly into the specimen cup, for example, girls (Valcke et al, 2006). Some specific brands of commode, ''potty'' or ''hat'' inserts used in previous studies include ''Specipan'' (Baxter Scientific, McGraw Park, IL, USA), lined potty chairs, 750 ml toilet seat inserts and inserts from Sage Products Inc., Crystal Lake, IL, USA (Loewenherz et al, 1997;Curl et al, 2002;Fenske et al, 2002;Shalat et al, 2003, Becker et al, 2008. Again, it should be ensured that sample cups and commode inserts are pre-screened and found to be devoid of the contaminant or metabolite of interest, such as phthalates (Brock et al, 2002).…”

“…The cotton insert may be frozen and shipped to the laboratory, where it is centrifuged to extract urine, although the volume recovered is often small (Calafat et al, 2004). Urine may also be extracted from the cotton pad through use of a disposable syringe on-site (Hu et al, 2000;Shalat et al, 2003;Zohouri et al, 2006) by placing the gauze into an empty syringe, replacing the plunger and squeezing urine into vials (Weuve et al, 2006). Alternatively, the urine can be aspirated from the pad using a syringe (Shalat et al, 2003;Dorey and Zimmermann, 2008).…”

“…Cotton inserts that have been used include: ''Surgipad'' (Johnson & Johnson, Skillman, NJ, USA), ''Organic Diaper Doublers'' cotton terry cloth inserts, and pads from Ontex Ltd. Northamptonshire, UK (Hu et al, 2000;Shalat et al, 2003;Zohouri et al, 2006).…”