Table 4.
Characteristics of published studies evaluating neurologic effects from prenatal or childhood exposures to organophosphate (OP) pesticides. The three US birth cohorts are listed first (study/year) followed by other studies in chronologic/alphabetic order.
| Author/cohort | Exposure assessment | Sample sizeb | Age | Neurodevelopmental assessment | Study design | Dose–response | Study rating (score) | OP pesticide(s) |
|---|---|---|---|---|---|---|---|---|
| Young et al. (2005) (CHAMACOS, CA, USA) | Repeated (2) maternal urinary DAPs | 381 | Neonates | BNBAS | CL | Y | High (8) | OP class exposure |
| Eskenazi et al. (2007) (CHAMACOS, CA, USA) | Repeated (2) maternal urinary DAPs, MDA, TCPY; children urinary DAPs | 396 395 372 |
6 mo 1 yr 2 yrs |
BSID-II (MDI/PDI); CBCL | CL | Y | High (10) | OP class exposure, malathion, chlorpyrifos via occupational/para-occupational |
| Eskenazi et al. (2010) (CHAMACOS, CA, USA) | Repeated (2) maternal and 2 year old urinary DAPs, PON1 genotype/activity in maternal cord | 353 | 2 yrs | BSID-II (MDI/PDI); CBCL | CL | Y | High (9) | OP class exposure, malathion, chlorpyrifos via occupational/para-occupational |
| Marks et al. (2010) (CHAMACOS, CA, USA) | Repeated (2) maternal urinary DAPs | 331 323 |
3.5 yrs 5 yrs |
CBCL; NEPSY-IIg K-CPT |
CL | Y | High (8) | OP class exposure, malathion, chlorpyrifos via occupational/para-occupational |
| Bouchard et al. (2011) (CHAMACOS, CA, USA) | Repeated (2) maternal urinary DAPs | 329 | 7 yrs | WISC-IV | CL | Y | High (9) | OP class exposure via occupational/para-occupational |
| Rauh et al. (2006) (Columbia, NY, USA) | Umbilical cord CPF | 254 | 1–3 yrs | BSID-II, CBCL | CL | Y | High (10) | CPF via indoor air |
| Rauh et al. (2011) (Columbia, NY, USA) | Umbilical cord CPF | 265 | 7 yrs | WISC-IV | CL | Y | High (10) | CPF |
| Rauh et al. (2012) (Columbia, NY, USA) | Umbilical cord CPF | 40 | 6–11 yrs | MRI, WISC-IV | CL | Y | High (8) | CPF via indoor air |
| Engel et al. (2007) (Mt. Sinai, NY, USA) | Maternal DAPs | 311 | Neonates | BNBAS | CL | Y | High (8) | OP class exposure |
| Engel et al. (2011) (Mt. Sinai, NY, USA) | Maternal DAPs, PON activity, genotype | 200 276 169 |
1 yr 2 yrs 6–9 yrs |
BSID-II (MDI/PDI); WPPSI-III; WISC IV | CL | Y | High (9) | OP class exposure |
| Dahlgren et al. (2004) (Family case study; CA, USA) | Air, wipe DZN | 5 | 5 mos-11 yrs | WPPSI-R NEPSY Blockg | CS | n/a | Low (0) | DZN |
| Rohlman et al. (2005) (OR and NC, USA) | Parent’s occupationa | 43/78 | 4–5 yrs | BARS, PENTBg | C | n/a | Intermediate (3) | OP pesticide not specified |
| Ruckart et al. (2004) (Superfund sites, USA) | Urinary PNP; MP surface wipes | 279 | <6 yrs | PENTB | CL | n/a | High (8) | MP from chronic high level residential exposures |
| Martos Mula et al. (2005) (Jujuy, Argentina) | Proximity to usea | 64/87 | 11–16 yrs | WISC-Rg, DVT | C | n/a | Low (1) | OP pesticide not specified |
| Eckerman et al. (2007) (Rio de Janeiro, Brazil) | Index score derived from a questionnaire | 66 | 10–18 yrs | BARS | C | n/a | Intermediate (3) | OP pesticide not specified |
| Grandjean et al. (2006) (Quito, Ecuador) | Maternal occupation; Child urinary DAPs, AChE activity | 37/72 | 6–8 yrs | WISC-Rg; Stanford-Binetg; Santa Ana Form Board | C | Y (reaction time only) | Intermediate (4) | OP class exposure |
| Kofman et al. (2006) (poisonings occurring <3 yrs age in Israel) | Hospital record abstraction of symptoms | 9/52 | 9 years | NEPSYg, WISC-Rg | CL | n/a | Intermediate (3) | OP class exposure |
| Rohlman et al. (2007) (Oregón, USA) | Occupationa | 50/77c | 12–60 years | BARS | C | n/a | Intermediate (3) | OP pesticide not specified |
| Handal et al. (2007a) (Ecuador) | Proximity to usea | 154/283 | 3–61 mos | ASQ | C | n/a | Intermediate (5) | OP pesticide not specified |
| Handal et al. (2007b) (Ecuador) | Proximity to use, parent’s occupation, child activitiesa | 142 | 24–61 mos | ASQ, VMI | C | n/a | Intermediate (4) | OP pesticide not specified |
| Lizardi et al. (2008) (Hispanic agricultural children in AZ, USA) | Child urinary DAPs | 48 | 5–8 yrs | WISC-IIIg, WCST, CMS, TMT(A&B), CBCL, TRF | C | n/a | Intermediate (3) | Dimethyl-OPs |
| Abdel Rasoul et al. (2008) (Menoufia, Egypt) | Child’s occupation, AChE | 50/100 | 9–18 yrs | WAISg, TMT(A&B), BVRT | C | n/a | Intermediate (3) | OP and carbamate class exposure |
| Handal et al. (2008) (Ecuador) | Maternal occupation during pregnancya | 121 | 3–24 mos | ASQ | C | n/a | Intermediate (4) | OP pesticide not specified |
| Bouchard et al. (2010) (NHANES 2000–2004, USA) | Urinary DAPs | 1139 | 8–15 yrs | DISC-IV from DSM-IV | C | Y | Intermediate (6) | OP class exposure |
| Harari et al. (2010) (Quito, Ecuador) | Maternal occupation; Child urinary DAPs, AChE activity | 35/87d 23/87e 22/87f |
6–8 yrs | WISC-Rg; Stanford-Binetg; Raven’s colored progressive matrices, Santa Ana Form Board, FTT | C | n/a | Intermediate (4) | OP class exposure |
| Muñoz et al. (2011) (Chile) | Urinary DAPs | 25 | 6–16 yrs | WISC-III | C | n/a | Intermediate (3) | OP class exposure |
| Guodong et al. (2012) (Shanghai, China) | Child urinary DAPs | 301 | 2 yrs | GDS | C | N | Intermediate (6) | OP class exposure |
Exposure assessment: AChE = acetylcholinesterase; CPF = chlorpyrifos; DAPs = dialkylphosphate metabolites of organophosphate insecticides; DZN = diazinon; MDA = malathion dicarboxylic acid (metabolite of malathion); MP = methyl parathion; PNP = para-nitrophenol (metabolite of methyl parathion); PON1 = paraoxonase; TCPY = 3,5,6-trichloropyridinol (metabolite of chlorpyrifos and chlorpyrifos methyl).
There is no certainty of exposure to OP pesticides specifically, and it could be assumed only as likely or potential.
Sample size
The sample number includes either the full population of the study or the exposed population/total population.
Exposed/total population only considering adolescent partipants.
Exposed during pregnancy via maternal occupation
Indirect exposure from paternal work
Current exposure irrespective of prenatal exposure.
Neurodevelopmental Assessment: For descriptions, see Table 2
Administered only selected sections of the full test or battery
Study design: C = cross-sectional; CL = cohort (longitudinal); CS = case study (no controls).
Dose/response: Y = Yes, N = No, n/a = non applicable (dose/response was not evaluated). Study Rating (see Table 3 for details): Low (0–2); Intermediate (3–7); High (8–10).
OP Pesticide(s): OP class exposure = Studies in which the assessment of exposure was made through biomarkers of OP residues that are not able to differentiate the specific type of pesticide used (e.g., DAPs metabolites).
OP pesticide not specified = Studies in which there were no measuring of metabolites or biomarkers, and the information was obtained only through a questionnaire, the occupation or the location of communities.