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Welcome to the City of Ogallala Risk Analysis Meeting

May 2, 2013

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What Happened in Ogallala?

• Residents began complaining about mental confusion, and eye, skin, and respiratory irritation– Some residents have also reported odd-looking fish from

Humphries Pond• Unidentified crystal residues seen in the town have been

analyzed and found to be cyanazine• Residents have reported that they witnessed three

teenagers take a truck belonging to Keith Backlash on a joy ride– Keith Backlash owns Red Storm Pest Control Company– That truck is used to spray pesticide and was loaded with

cyanazine• As the teenagers drove around, they sprayed cyanazine

– A container fell off the truck and into Humphries Pond– Container filled with cyanazine as well

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Risk AssessmentRisk Assessment is a process used to determine the nature and magnitude of human and environmental health risk to exposure of a chemical or any other substance• Aims to identify nature and probability of

adverse health effects on humans

Hazard Identification

Dose Response Assessment

Exposure Assessment

Risk Characterization

Risk Management

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Structural Activity Relationship

• Baldex, Fortol, Payze• C9H13CIN6

• Synthetic chemical used as a herbicide in agricultural crops– Registered for use on corn, cottonseed, sorghum,

and wheat• Categorized as part of the triazine family of herbicides• White crystals at 25 oC• NOEL (No Observable Effect Level): 1.25 mg/Kg/day• ADI (Acceptable Daily Intake): 0.0013 mg/Kg/day• Cyanazine is structurally related to the compounds

Simazine, Atrazine, Propazine and Terbutryn

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In Vitro Studies• Study 1:

– 23 pesticide tested in aquatic environment– Concentration in accordance to the expected

environmental concentrations – Tested on 4 species of algae, species of cyanobacteria

and one species of duck weed– Cyanazine had a high hazard to all test species

• Study 2– 2-30mL was taken from 4 healthy non-smoking adults

not on any medication – Leukocyte rich plasma was obtained after blood has

settled – Exposed to cyanazine (1ug/mL, 0.1ug/mL, and

0.01ug/mL) – Shows that 1ug/mL was enough to cause chromosomal

damage

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Animal Bioassays• Study 1:Rat

-GABAA receptor located in the hypothalamus-Hypothalamus resposible for:-LH and GnRH

• Atrazine:–

testosterone/LH/GnRH– Inhibition of GnRH

release of hormones:– Alters reproduction and

growth

• Study 2:Rainbow fish– Age of onset of functional

liver metabolism rainbowfish– Two known major pathways:

• oxidation in the liver toxic metabolite and glutathione conjugation

• Study 3: Maternal Toxicity in rat pups and rabbits– Malformations:

• eye-defects (microphthalmia) and thoracoschisis along with microphthalmia

• correlation of fetal development and the occurrence of maternotoxic signs

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Epidemiological Studies• 1st Study: cyanazine– Cohort study: cancer incidence– 57,311 pesticide applicators evaluated– Exposure details: questionnaire– Pesticide applicators had ≥ 6 years of exposure – Results: no clear correlation

• 2nd Study: triazine– Ecologic study: breast cancer– Exposure details: state registry– Created a summary index of triazine exposure– Results: increase in breast cancer

CyanazineAnimals-Oral Toxicity LD50Rats 182mg/kg-332mg/kgMice 380mg/kgRabbits 141mg/kgMallards (Birds) >2000mg/kgBobwhite Quail 400mg/kgBees 0mg/kg (non-toxic)

Aquatic Animals LC50Harlequin Fish 7.5mg/LSheepshead Minnow 18mg/L

Animals-Dermal Toxicity LD50Rabbits >2000mg/kgRats >1200mg/kg

Animals-Inhalation Toxicity LC50Rats 2.28mg/L/hr

Animals-Teratogenic Toxicity LD50Fischer Rats 25mg/kg/day 9

AtrazineMaximum Contaminant Level 3.0 μg/L of water

NOAEL 2mg/kg of body weight/dayNOAEL – Bob White Quail >5,000ppm

Oral in humans 0.01mg/kg/day (acute expocute exposure)

Oral in humans 0.003mg/kg/day (intermediate exposure)

Animal Toxicity LD50Rats (Oral) 672mg/kgMice (Oral) 850mg/kgRabbits (Oral) 750mg/kgHamsters (Oral) 1,000mg/kgBirds (Oral) >2,000mg/kgRabbits (Dermal) 7,500mg/kgRats (Dermal) >3,000mg/kg

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Toxicological EffectsCyanazine :moderately toxic to mammals• Symptoms:

• labored breathing• blood present in saliva• depression, and inactivity. • mild irritant (slight toxicity via inhalation)

• Long term exposure • decreased body weight and an increase in liver

weight.• Teratogenic effects (birth defects)

• increased brain weights• decreased kidney weights• incomplete bone development• underdeveloped eyeballs. 11

Dose ExposureWater Ingestion Dose

(mg/kg/day)Adult man 0.24

Adult woman 0.29

Child 0.525

Infant 0.841

Water Dermal Absorption Dose

(mg/kg/day)Adult man 0.143

Adult woman 0.151

Male Child 0.235

Female Child 0.23012

Fish Ingestion Exposure Dose(mg/kg/day)

General population—all fish

8.15 e-5

Recreational fishers—freshwater fish

1.014 e-4

Subsistence fisher—all fish 6.90 e-4

Fish Ingestion Dose (mg/kg/day)

Bluegill 8.17

Channel Catfish 0.247

Largemouth Bass 1.53

Rainbow Trout 2.3413

Spraying Truck

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Air Concentration of CyanazineDefault Air

Intake Rates (m3/day)

Mansion on the hill & Best

Western Stagecoach Inn

Highway 3018m away Highway 30

530m away

Air Concentration

(mg/ m3or ppm)

74 mg/ m3 or 7.52 ppm

140.6mg/m3

14.28ppm13.14mg/m3

1.33ppm

Inhalation Exposure Dose

(mg/kg/day)Adult Male 15.2 16.1 30.53 2.85

Adult Female 11.3 14.4 27.39 2.56

Children 10 46.25 87.88 8.21

Infants 4.5 33.3 63.27 5.9

Skin Exposure Dose to Cyanazine

Air Particulate (mg/hr) (with SA of head, neck, and upper

limbs)

9.2 x 10-4 (with total surface are of 4860 cm2)

1.75 10-3 1.6 10-4

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18m

500m

>140.6mg/m3

>13.14mg/m3

Soil Concentration & Exposure of Cyanazine

Around Humphries

Pond

Mansion on the hill & Best

Western Stagecoach Inn

Highway 30 18m away

Highway 30530m away

Soil Conc. (g/cm3)

0.0022 mg/ cm3 4.2 x 10-8 8 x 10-8 7.5X10-9

Skin Exposure Dose of Soil

(mg/hr)Adult (Hand SA

720 cm2)0.004 7.7 x 10-5 1.47x10-4 1.38 x10-5

Child (Hand SA 240 cm2)

0.0014 2.6 x 105 4.9x10-5 4.8x10-6

Soil Ingestion Exposure Dose

(mg/kg/day)Child 2.1 x 10-5 5.3 x 10-13

Pica Child 5.1 x 10-4 1.3 x 10-11

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Risk Characterization- Fish Exposure

Fish Ingestion Dose in

Humphries Pond

(mg/kg/day)

Dose Response Data

Analysis of Exposure to Cyanazine Risk

Bluegill 8.17 LC50-Harlequin Fish 7.5 mg/L

Potential Teratogenicity Risk

No toxic effect to the adult fish currently in

Humphries PondChannel Catfish 0.247

Largemouth Bass 1.53 LC50- Minnow 18 mg/L

Rainbow Trout 2.34

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Risk Characterization: Inhalational Exposure

Mansion on the hill & Best

Western Stagecoach Inn

Highway 30

18m away

Highway 30

530m away

Dose Response Data

Analysis of Exposure to Cyanazine (Risk or

no Risk)

Inhalation Exposure Dose (mg/kg/day)

LOAEL: 0.16mg/kg/day

Adult Male 16.1 30.53 2.85 Inhalational TD: 59.35 mg/kg

Slight Risk: coughing, nasal discharge

Adult Female 14.4 27.39 2.56 Slight Risk: coughing, nasal discharge

Children 46.25 87.88 8.21 Inhalational TD: 66.97mg/kg

Moderate Risk: respiratory irritation

Infants 33.3 63.27 5.9 Moderate Risk: respiratory irritation

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Risk Characterization - IngestionWater

Ingestion from

Humphries Pond

Soil Ingestion from

Humphries Pond

Soil Ingestion from Mansion

on the Hill

Ingestion of cyanazine

contaminated fish

Dose Response Data

Analysis of Exposure to

Cyanazine (Risk or no Risk)

Subpopulations General Population:

0.0000815 mg/kg/day

LD50- 29.5 mg/kg/day

NOAEL:

80.16 mg/kg/day

Teratogenicity:

NOAEL: 1.62mg/kg/day

TD: 1.297 mg/kg/day

No Toxicity based on ingestion

Concern for pregnant

women and children

Adults 0.25 mg/kg/day

Children 0.525 mg/kg/day

2.1 x 10-5 mg/kg/day

5.3 x 10-13 mg/kg/day

Infants 0.841 mg/kg/day

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Risk Characterization- Dermal

Direct Dermal Contact– Swimming in Humphreys Pond

• Adult male: 0.143mg/kg/day • Adult Female: 0.151mg/kg/day• Male child: 0.235mg/kg/day • Female Child: 0.230mg/kg/day

– Soil-Hand contact near Humphrey’s Pond• Adult: 0.004mg/hr • Child: 0.0014mg/hr

– Soil-Hand Contact near the Best Western Stagecoach and the Mansion on the Hill• Adult: 7.7x10-5mg/hr• Child: 2.6x10-5mg/hr

Air Dermal Contact – 18 meters away

• 0.00175mg/hr– 540 meters away

• 0.00016mg/hr

• Soil-Dermal Contact (from air contamination)– 18 meters away

• adult: 1.47x10-4mg/hr – 18 meters away

• child: 4.9x10-5mg/hr– 540 meters away

• adult 1.38x10-5mg/hr– 540 meters away

• child: 4.8x10-6mg/hr

Human equivalent LD50 found in rats = >194.59mg/kgNo Observed Adverse Effect Level= 2.0mg/kg/day

Risk Characterization- Dermal

• Conclusions:– LD50

• No severe toxicity or lethality should be observed.• All dermal exposure values are significantly less than the

human equivalent LD50 dose in rats (>194.59mg/kg)– NOAEL

• No adverse effects should be seen • All dermal exposure values are less than the human equivalent

NOAEL dose in rats (2.0mg/kg/day)– Therefore, dermal exposure to the cyanazine levels to the

public is not of grave concern– However, protect yourself for the time being, do not swim

in Humphrey’s pond and wear gloves when working with soil

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Restrictions Immediately Following Ogallala Incident

After accidental release of the chemical, cyanazine, the Risk Management team intends on maintaining public safety by enforcing the following restrictions until further notice:

Halt the use of tap water (water supply may be contaminated) Do not walk outdoors with edibles (cyanazine present in air) Wear protective face mask (provided by Ogallala Police Department

near each contaminated site) DO NOT clean up the white powdered substance, report to police

officer and/or the hotline

1. Humphrey’s Pond City Park CLOSED until further notice No human activity near the

area (fishing, walking running, etc…)

1. A & W (Fairgrounds) Restaurant

CLOSED until further notice

1. Best Western Stagecoach Inn & surrounding locations

Remain indoors until further notice

If you are exiting, utilize protective equipment provided by the Inn

1. Mansion on the Hill CLOSED until further notice1. Highway 30 Before entrance, collect

protective wear Decreased speed limit

For those who have been exposed or begin to experience side effects after being in these contaminated sites, seek treatment at Ogallala Community Hospital and report to hotline 1-888-OGALLAL (642-5525).

RM Regulatory Actions

• Stricter– Labeling regulations – storage regulations

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Contaminated Sites

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Remediation Actions• Humphrey’s Pond– Surface soil

removal/cleansing• Phytoremediation• Excavation

– Water Filtration• Covalent

sequestration

• A & W (Fairgrounds)

• Best Western Stagecoach Inn

• Mansion on the Hill– Surface soil

removal

• Highway 30– Street cleaning

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Resources for Ogallalians• 1-888-OGALLAL (642-5525)– Voice concerns –white powder substance findings– Signs & symptoms

• http://ogallalatox.wordpress.com/– Blog with updates on Ogallala incident

• Mobile command units near each contamination site– Immediate assistance

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