Farm family exposure to 2,4-D DuPont, Dow U Minn Public Health American Chemistry Published in Environmental Health Perspectives

2,4-D characteristics Moderate acute oral LD 50 (~ 350 mg/kg) Not considered to cause mutagens, not likely to be a carcinogen, no likely effect on reproductive system or development at human exposure rates Dermal penetration about 7% of skin dose

Study Purpose Identify real-world pesticide exposure and factors before, during, and after application 2, 4-D widely used in ag and non-ag applications Ranked 5 th in ag uses – 2001 #1 in home, garden uses

Participants Certified pesticide applicators – South Carolina & Minnesota Farmer, spouse, 1+ child 4 to 17 years old Live on farm Farm at least 10 acres within 1 mi of home Both amine and ester forms used

Answer questions and allow observation Collect all urine for 5 consecutive days – day before, application day, 3 consecutive days after Allow field observer to document weather, application practices, family activities Participants

Characteristics 34 families – 17 MN 17 SC Average age - farmer 43.6y, spouse 40.2y 53 children – 10.2y (4-17) Applications during spring and early summer

Practices – survey responses None had applied 2,4-D within 7 days before study No spouses had mixed pesticides within 1 week of study 2,4-D detectable in 70% of applicators, 62% of children, and 41% of spouses in pre-application urine samples

Practices 44% used enclosed cab tractors 26% < 25 ac; 30% - 25 to 74 ac; 44% > 75 ac 26% - 1 to 2 loads; 41% - 3 to 5 loads; 33% - 6 or more loads

Spray day observations 71% wore rubber gloves – during mixing /loading/ application 47% had some contact w/ 2,4-D 24% spouses & 38% (20) children present during some of mix/load/ spray 1 spouse & 8 children had chance for direct pesticide contact

Spray day observations 11% ate during application 32% used tobacco during application 35% had spills during mixing and /or loading 62% repaired equipment during the application 65% spouses washed spray clothing

Results – Applicator

2,4-D in urine (ugm/L) Peak urine concentration 1 day after application Biological half-life 17 hrs

2,4-D in urine (ugm/L) Yes No Wore rubber gloves Closed cab Spill or accident Observed skin contact Equipment repair Used tobacco Ate while spraying

2,4-D in urine (ugm/L) Acres 75 treated No. of loads >

Factors associated with INCREASE in urinary 2,4-D concentrations Did not wear gloves Treated more acres Repaired equipment

2,4-D doses (mg/kg body wt) GroupAverage dose Maximum dose Applicators Spouses Children 4 – Children > Spouses and children present at some time during mixing / loading / spraying received greater doses than those not present

Limits of study Only one application evaluated per family All were tractor boom sprayer applications Participation in study may have affected behavior of applicators

Some lessons Application of 2,4-D resulted in exposure of applicator and family members \ Amount of exposure was determined by potential for direct contact with the pesticide Use of rubber gloves when mixing, loading, and applying 2,4-D and repairing equipment was associated with greatly reduced urinary concentrations of 2,4-D Reduce children’s potential for contact

Reminders 2,4-D metabolism in the body is very different than that for other pesticides Actions that reduce exposure result in lower absorption of 2,4-D