In an attempt to control a serious bedbug problem, the owner of a duplex rental property located on 2352/2354 Warsaw Avenue in Cincinnati, Ohio hired an unlicensed applicator (UA) to spray a pesticide in both rental units to exterminate the bedbug problem.
The UA purchased an insect spray from a national hardware store called “Spectracide”. The insect spray contained 50% Malathion and was labeled as only to be used in outdoor applications.
On June 2, 2010, the UA sprayed the Warsaw property in the morning and again in the late afternoon. Later that evening, a few of the tenants in Unit #1 (2352 Warsaw) began showing symptoms, such as headaches, lightheadedness, nausea and severe diarrhea. The tenants in Unit #1 compose of 3 adults and 4 children (6-years old and younger). In addition, the tenants in Unit #2 (2354 Warsaw) also began showing symptoms, such as diarrhea, nausea, vomiting, headaches, sweating and muscle fatigue. The tenants in Unit #2 compose of 2 adults.
On June 3, 2010, the UA again sprayed the Warsaw property in the morning and again in the late afternoon.
On June 4, 2010, the UA sprayed the Warsaw property once in the morning. Later that evening, an adult in Unit #1 began showing symptoms. Calls were made to the pesticide manufacturer and the manufacturer told the tenants that they should go to the hospital. The tenants then went to Mercy Hospital, Children’s Hospital or the University Hospital for treatment. Five of the tenants received 2-PAM4 shots.
On June 7, 2010, the City of Cincinnati Fire Department (CFD) submitted a restraining order against the UA.
On June 8, 2010, the CFD issued an official “Vacate Order” against the Warsaw duplex property. The tenants from the two units vacated the property and relocated to relatives homes.
On June 9, 2010, the City of Cincinnati Health Department (CHD) posted the Warsaw property as “Unfit for Human Habitation”. The City of Cincinnati Police Department officially taped off the two contaminated units to prevent/prohibit the removal of any items from the occupied units, at the request of U.S. EPA and the ODA Criminal Investigations Unit.
On June 4, 2010, the Ohio Department of Agriculture (ODA) mobilized to the site, stopped the UA from applying the second round of spraying in the evening and collected seven swab samples to determine the pesticide that was used at the property. The swab samples were analyzed by the ODA Laboratory located in Reynoldsburg, Ohio.
Analytical results showed the following malathion concentrations:
• Single Mattress in the Upper East Bedroom (Unit #1) – 472.8 micrograms (μg)
• Baby Mattress in the Upper East Bedroom (Unit #1) – 581.1 μg
• Mattress in the Upper West Room (Unit #1) – 536.95 μg
• Couch Cushion in the Living Room (Unit #1) – 40.7 μg
• Mattress in the Lower Room (Unit #2) – 30.8 μg
• Table top in the Living Room (Unit #2) – 7,846.6 μg
• Living Room sofa cushion (Unit #2) – 1,165.5 μg
On June 10, 2010, the ODA and CHD requested U.S. EPA assistance to conduct air sampling to determine the extent of malathion contamination inside the duplex and to assist coordinating the decontamination of a Malathion-contaminated property.
On June 24, 2010, U.S. EPA and WESTON START began the environmental characterization of the interiors of the two units of the duplex. WESTON START collected six Polyurethane Foam (PUF) sorbent tube air samples and two summa canister air samples from the rental property.
Analytical results for malathion from the seven PUF air samples were as follows:
• Unit #1 Basement - 4.46 micrograms per cubic meter (ug/m3)
• Unit #1 1st floor Living Room - 5.57 ug/m3
• Unit #1 2nd floor Kid's Bedroom - 24.58 ug/m3
• Unit #2 Basement - 3.74 ug/m3
• Unit #2 1st floor Living Room - 6.64 ug/m3
• Unit #2 2nd floor Master Bedroom - 9.63 ug/m3
• Ambient - non detect
ATSDR established the following malathion indoor air action level --> 20 ug/m3
The SUMMA canister air samples were analyzed for volatile organic compounds (VOCs) using U.S. EPA Method TO-15. Analytical results from the two SUMMA canister air samples did not show any VOCs at concentrations greater than each respective chemicals TLV-TWA value.
To determine the extent of malathion contamination within each of the duplex units, on June 30, 2010, WESTON START mobilized two 2-person sampling teams and entered the property in Level C PPE with APRs and/or PAPRs. START collected 23 wipe samples from Unit #1 and 17 wipe samples from Unit #2. The wipe samples were collected from baseboards, walls (2-feet above baseboards and 5-feet above baseboards), countertops, appliances, and hardwood or linoleum flooring.
The wipe sample analytical results from Unit #1 showed malathion detections in 10 of the 23 wipe samples collected, with a high malathion concentration of 8.16 micrograms per 100 square centimeters (ug/100cm2).
The wipe sample analytical results from Unit #2 showed malathion detections in 10 of the 17 wipe samples collected, with a high malathion concentration of 56.3 ug/100cm2. ATSDR established a wipe sample malathion action level of 15 ug/100cm2. The only wipe sample that showed a malathion concentration greater than the 15 ug/100cm2 action level was collected from a 2nd floor bedroom wood threshold than separated the carpet between rooms. Isomalathion and the malathion oxygen analog were also analyzed in each wipe sample. Isomalathion was detected in only one wipe sample (the wipe sample that exceeded the malathion action level) at 1.61 ug/100cm2. The malathion oxygen analog was not detected in any wipe sample.
On July 28, 2010, the property owner hired Environmental Enterprised Incorporated (EEI) to conduct a removal action at the property. EEI filled three 20-cubic yard rolloff boxes with porous items (clothing, carpet, etc) (malathion-contaminated items) and sprayed and wiped down all non-porous items in each duplex with a bleach solution.
On July 29, 2010, WESTON START mobilized to the Site and collected three post-decontamination PUF air samples from each unit, including an ambient air sample. The PUF air samples were collected over an 8-hr time period.
Analytical results for malathion from the seven PUF air samples were as follows:
• Unit #1 Basement - 1.37 ug/m3
• Unit #1 1st floor Living Room - 0.648 ug/m3
• Unit #1 2nd floor Kid's Bedroom - 2.874 ug/m3
• Unit #2 Basement - 1.931 ug/m3
• Unit #2 1st floor Living Room - 2.074 ug/m3
• Unit #2 2nd floor Master Bedroom - 0.846 ug/m3
• Ambient - non detect
ATSDR established the following malathion indoor air action level --> 20 ug/m3
None of the PUF air samples showed malathion detections greater than the ATSDR malathion indoor air action level. The air samples were also analyzed for isomalathion and the malathion oxygen analog. All seven PUF air samples showed not detect for both analytes.
On July 29, 2010, ODA mobilized to the site and collected 3 post-decontamination wipe samples from Unit #1 and 4 post-decontamination wipe samples from Unit #2.
ODA wipe sample analytical results showed the following:
• Unit #1 Master Bedroom (floor sample) --> Malathion = 262.5 ug/100cm2; Isomalathion = 1.35 ug/100cm2 and the Malathion Oxygen Analog = 24.85 ug/100cm2
• Unit #1 Living Room (baseboard sample) --> Malathion = 64.1 ug/100cm2; Isomalathion = non detect and the Malathion Oxygen Analog = 0.696 ug/100cm2
• Unit #1 Master Bedroom (baseboard sample) --> Malathion = 371 ug/100cm2; Isomalathion = 18.1 ug/100cm2 and the Malathion Oxygen Analog = 11 ug/100cm2
• Unit #2 Bedroom #2 (wood threshold) --> Malathion = 445.5 ug/100cm2; Isomalathion = 14.35 ug/100cm2 and the Malathion Oxygen Analog = 4.56 ug/100cm2
• Unit #2 Living Room (high traffic area sample) --> Malathion = 215 ug/100cm2; Isomalathion = 61.4 ug/100cm2 and the Malathion Oxygen Analog = 9.37 ug/100cm2
ODA wipe samples showed elevated malathion concentrations and detectable isomalation and malathion oxygen analog concentrations in each unit. ODA believes that the use of bleach as the decontamination agent by EEI did not thoroughly clean the non-porous items in each unit and also may have broken down the malathion into isomalathion and the malathion oxygen analog.
In August 2010, the property owner removed the wooden threshold in Unit #2, polyurethaned the wood subfloor, installed new subfloor and then installed new carpet in Unit #2. The property owner also applied polyurethane and painted the baseboards in Unit #2.
On November 29, 2010, the CHD informed the owner of the Warsaw property that it was removing the "Unfit for Human Habitation" posting on 2354 Warsaw Avenue (Unit #2).
As of June 2011, Unit #2 is occupied with a new tenant and Unit #1 is still vacant. The property owner still has plans to polyurethane the wood subfloor, installed new subfloor and then install new carpet in Unit #1. The property owner also still has plans to apply polyurethane and paint the baseboards in Unit #1.
The project was completed on April 3, 2012. See POLREP #1 for details.
