bcsd beaufort county, south carolina · brought to the attention of the bcsd that rubber gym...

Terracon Consul tants, Inc. 1450 Fif th Street West North Charleston, South Carol ina 29405P [843] 884 1234 F [843] 884 9234 terracon.com

August 9, 2018

Beaufort County School District2900 Mink Point RoadBeaufort, South Carolina

Attn: Mr. Robert S. Oetting, PEFacilities Planning and Construction OfficerE: [email protected]

RE: Report of FindingsMercury in Gym Evaluation and Air TestingHilton Head School of the Creative Arts, Beaufort Middle School, Robert Smalls Academy,and Island AcademyBeaufort County, South CarolinaTerracon Project No. EN187166

Dear Mr. Oetting:

Terracon Consultants, Inc. (Terracon) is pleased to present the results of the air testingconducted on August 1 and 2, 2018, at four (4) schools in the Beaufort County School District.The air monitoring was conducted in general accordance with our proposal PEN187166, datedJuly 25, 2018

1.0 PROJECT INFORMATION

Terracon entered into a contract agreement with BCSD dated March 18, 2018, to provideconsulting services under RFP #18-018, Indoor Air Quality Program.

During the asbestos testing in conjunction with 2018 Renovation Program, it was requested totest the gym floor mastic for asbestos at Hilton Head School of the Creative Arts. Terraconbrought to the attention of the BCSD that rubber gym floors, such as the floor currently in placeat HHSCA, was known to contain mercury. The gym floor and airborne conditions at theHHSCA gym were tested and a report issued dated July 6, 2018. The district discovered therubber flooring was present at three (3) additional schools. At the direction of the BCSD,additional gym floor samples were collected from Beaufort Middle School, Robert SmallsAcademy, and Island Academy. The results were each sample of the gym floor containedlevels of mercury from each school gym that ranged from 248 milligrams per kilogram (mg/kg) to394 mg/kg.

2.0 SCOPE OF SERVICES

Based on the findings at HHSCA, Terracon recommended the following air testing evaluationplan:

Mercury in Gym Floor EvaluationBCSD ■ Beaufort County, South CarolinaAugust 9, 2018 ■ Terracon Project No. EN187166

Responsive ■ Resourceful ■ Reliable 2

2.1 Methods

Terracon performed an initial site assessment to determine the level of hazard from mercuryvapors within the gym. The assessment was performed using a direct reading Arizona JeromeJ405 mercury vapor analyzer. The Jerome J405 is a direct reading instrument that providesinstantaneous results in the field. Sampling was performed inside the gym and outside inadjacent spaces. Based on previous testing at HHSCA, we recommend the following:

§ Day 1 Testing – HVAC system shall remain in normal operation throughout Day 1 withnormal nighttime settings. After testing is completed on Day 1, all HVAC equipment forthe gym shall be shut off at the end of the day at each school. Testing in the gym willbegin in the next morning at 8:00. Several locations will be tested throughout the gym.After testing is completed (approximately 10:00), turn on HVAC system in normaloperation and then perform testing after 2-3 hours of normal operation.

§ Day 2 Testing – Testing in the gym will began in the morning. Several locations will betested throughout each gym. After testing was completed, the HVAC system was returnedto normal operations and testing was performed approximately 2-3 hours of normaloperation.

2.2 Evaluation Criteria

The Agency for Toxic Substances Disease Registry (ATSDR) guideline document provides thefollowing information based on mercury spills in residential and school environments:

Consideration should be given to closing or isolating areas of schools with mercuryconcentrations of ≥ 10 µg/m3, depending on the exposures. ATSDR recommends a range of ≤ 3µg/m3 before resuming normal operations of the school. This recommendation is based on theresidential action levels and adjusted for a normal school day. Presuming all visible mercury inthe setting has been removed, this action level is considered appropriate.1”

Based on the ATSDR guidelines Terracon has adopted a reference target value for mercuryvapor in the school gyms that are being monitored at <3.0 micrograms per cubic meter (µg/m3).Gyms that exhibit mercury vapor concentrations below the target value are consideredacceptable for routine use until abatement of the rubberized flooring material can be conducted.

In addition to ATSDR reference guide, Dr. Michael Gochfeld, MD, PhD of Rutgers RobertJohnson Medical School and School of Public Health provided a letter of opinion, dated March1, 2017, for the Burlington Township Schools of Burlington, New Jersey in regards to mercury

1 ATSDR, 2012. Agency for Toxic Substances and Disease Registry. Chemical-Specific HealthConsultation for Joint EPA/ATSDR National Mercury Cleanup Policy Workgroup Action Levels forElemental Mercury Spills www.atsdr.cdc.gov.



exposure from rubberized gym flooring containing mercury. These documents are provided inAppendix II.

Dr. Gochfeld summarizes recommended mercury in air concentrations by various agencies.The agencies include:

· The Occupational Safety and Health Administration (OSHA)· National Institute of Occupational Safety and Health (NIOSH)· Agency for Toxic Substances and Disease Registry (ATSDR)· The Environmental Protection Agency (EPA)· California OSHA· Minnesota Department of Health (MDH)

These agencies report the air concentrations in different units of measurement; from milligrams(mg) to micrograms (µg) to nanograms (ng). For the purpose of aiding with conversion, pleaseuse:

3.0 RESULTS

The air testing evaluation was conducted during normal school hours on a representative schoolday and the next with the HVAC not in operation as outlined above. Terracon collected 25-30readings in each gym using the Jerome J405 mercury vapor analyzer. The readings werecollected in a grid-like pattern in the gym.

A summary of the results:

Ø August 1, 2018 – Day 1 HVAC Normal Operationsn HHSCA Readings ranged from 0.00 µg/m3 to 1.08 µg/m3 ;

AVG = 0.20 µg/m3 or 200 ng/m3

n Robert Smalls Readings ranged from 0.00 µg/m3 to 2.55 µg/m3 ;AVG = 0.67 µg/m3 or 670 ng/m3

n Island Academy Readings ranged from 0.00 µg/m3 to 0.51 µg/m3

AVG = 0.44 µg/m3 or 440 ng/m3

The first 3-4 readings (data summary in Appendix I) at Island Academy were collected inthe classrooms adjacent to the gym; which previously was a part of the gym.

n Beaufort Middle Readings ranged from 0.00 µg/m3 to 1.77 µg/m3;AVG = 0.17 µg/m3 or 170 ng/m3

1 µg = 0.001 mg = 1,000 ng



Ø August 2, 2018 – Day 2 HVAC OFF for ~ 12 hoursn Robert Smalls Readings ranged from 0.63 µg/m3 to 2.35 µg/m3;

AVG = 1.48 µg/m3 or 1480 ng/m3

n Island Academy HVAC was not shut off therefore the readings were similar toprevious day

n Beaufort Middle Readings ranged from 1.47 µg/m3 to 3.26 µg/m3;AVG = 2.52 µg/m3 or 2520 ng/m3

Ø August 2, 2018 – Day 2 HVAC turned onn Robert Smalls Readings ranged from 0.00 µg/m3 to 1.26 µg/m3

AVG = 0.71 µg/m3 or 710 ng/m3

n Beaufort Middle Readings ranged from 0.99 µg/m3 to 2.02 µg/m3

AVG = 1.15 µg/m3 or 1150 ng/m3

Mercury vapor was detected below the ATSDR target value of 3 µg/m3 in the four (4) gyms ateach school with the exception when the HVAC was shut off. With the HVAC off, the readingsincreased as anticipated and the readings were generally decreasing as the HVAC wasreturned to normal operations.

The summary of the downloaded data is provided in Appendix I.

4.0 RECOMMENDATIONS

Based on the evaluation results, Terracon recommends the following:

1. The HVAC contractor should conduct an inspection of system to ensure normaloperations and fresh air damper controls are functioning properly,

2. Increase the ventilation rates in the gym, i.e., a minimum of 15 cfm/person,

3. Consider increasing the operating time period by a minimum of one (1) hour prior tooccupancy,

4. Lower the temperature set point to 68ºF to reduce vaporization of mercury,

5. Consider periodic monitoring late summer (prior to school resuming) and early spring.This is typically the hotter months or when the temperature begins to increase.

5.0 GENERAL COMMENTS

The level of effort and associated tasks completed for this assessment were limited to the scopeof services outlined in Terracon’s proposal PEN187166 dated July 25, 2018, Terracon did notattempt to identify every potential exposure or hazard present in the subject building.



The results, findings, conclusions, and recommendations expressed in this report are based onconditions observed on August 1 and 2, 2018. Many factors such as workload, variations inwork material composition, work processes, and weather conditions can affect exposureconcentrations and air monitoring results. The information contained in this report should not berelied upon to represent conditions that existed previously or at a later date. Terracon does notwarrant the services of regulatory agencies, laboratories, or other third parties supplyinginformation, which may have been used in the preparation of this report. No warranty, expressor implied is made.

This report is prepared for the exclusive use of our Client for the specific application to the projectdiscussed and has been prepared in accordance with generally accepted industrial hygienepractices. In the event any changes in nature or location of processes, materials, or otherconditions as outlined in this report are observed, the conclusions contained in this report cannotbe considered valid unless the changes are reviewed and the conclusions of this report aremodified or verified in writing by the industrial hygienist.

Terracon appreciates the opportunity to provide these services to you. If we can provide anyadditional environmental, occupational health, or safety-related services, please contact us at843-277-8402.

Sincerely,Terracon Consultants, Inc.

Craig C. Langford T.A. (Andy) Rowland, III CIHSenior Industrial Hygienist National Director of Industrial Hygiene and

TrainingApproved Project Reviewer

APPENDIX I

Jerome Model: J405-0007 Serial Number: 405-00952Mercury Vapor Evaluation with HVAC in NormalOperatingAugust 1, 2018

Hilton Head School of the Creative ArtsDate Time Result/Units01-AUG-2018,08:34:04, 0.00, ug/m3,01-AUG-2018,08:34:31, 0.79, ug/m3,01-AUG-2018,08:34:52, 1.08, ug/m3,01-AUG-2018,08:58:21, 0.00, ug/m3,01-AUG-2018,09:49:28, 0.00, ug/m3,01-AUG-2018,09:50:17, 0.00, ug/m3,01-AUG-2018,09:50:51, 0.00, ug/m3,01-AUG-2018,09:51:47, 0.00, ug/m3,01-AUG-2018,09:52:11, 0.91, ug/m3,01-AUG-2018,09:52:36, 0.69, ug/m3,01-AUG-2018,09:53:12, 0.69, ug/m3,01-AUG-2018,09:53:41, 0.59, ug/m3,01-AUG-2018,09:54:06, 0.66, ug/m3,01-AUG-2018,09:54:34, 0.00, ug/m3,01-AUG-2018,09:54:58, 0.00, ug/m3,

Date Time Result/Units01-AUG-2018,09:55:21, 0.00, ug/m3,01-AUG-2018,09:55:48, 0.00, ug/m3,01-AUG-2018,09:56:11, 0.00, ug/m3,01-AUG-2018,09:56:35, 0.00, ug/m3,01-AUG-2018,09:57:00, 0.00, ug/m3,01-AUG-2018,09:57:23, 0.00, ug/m3,01-AUG-2018,09:57:54, 0.00, ug/m3,01-AUG-2018,09:58:18, 0.00, ug/m3,01-AUG-2018,09:59:43, 0.00, ug/m3,01-AUG-2018,10:05:50, 0.00, ug/m3,01-AUG-2018,10:06:44, 0.00, ug/m3,01-AUG-2018,10:07:17, 0.00, ug/m3,01-AUG-2018,10:07:41, 0.00, ug/m3,01-AUG-2018,10:08:48, 0.00, ug/m3,01-AUG-2018,10:11:33, 0.00, ug/m3,01-AUG-2018,10:13:31, 0.00, ug/m3,01-AUG-2018,10:15:00, 0.00, ug/m3,

Robert Smalls AcademyDate Time Result/Units01-AUG-2018,12:20:00, 0.00, ug/m3,01-AUG-2018,12:20:27, 0.00, ug/m3,01-AUG-2018,12:20:57, 0.00, ug/m3,01-AUG-2018,12:21:43, 0.00, ug/m3,01-AUG-2018,12:22:14, 0.00, ug/m3,01-AUG-2018,12:22:45, 1.07, ug/m3,01-AUG-2018,12:23:09, 1.63, ug/m3,01-AUG-2018,12:23:51, 0.88, ug/m3,01-AUG-2018,12:24:29, 1.06, ug/m3,01-AUG-2018,12:25:02, 1.12, ug/m3,01-AUG-2018,12:25:22, 1.07, ug/m3,01-AUG-2018,12:25:54, 1.35, ug/m3,01-AUG-2018,12:26:28, 1.19, ug/m3,01-AUG-2018,12:26:51, 0.00, ug/m3,01-AUG-2018,12:27:23, 1.44, ug/m3,01-AUG-2018,12:27:54, 1.44, ug/m3,

Date Time Result/Units01-AUG-2018,12:28:26, 1.57, ug/m3,01-AUG-2018,12:28:53, 2.55, ug/m3,01-AUG-2018,12:29:17, 1.71, ug/m3,01-AUG-2018,12:29:53, 0.00, ug/m3,01-AUG-2018,12:30:21, 0.00, ug/m3,01-AUG-2018,12:30:51, 0.00, ug/m3,01-AUG-2018,12:31:26, 0.00, ug/m3,01-AUG-2018,12:32:08, 0.00, ug/m3,01-AUG-2018,12:32:43, 0.00, ug/m3,01-AUG-2018,12:33:16, 0.00, ug/m3,01-AUG-2018,12:33:42, 0.00, ug/m3,01-AUG-2018,12:34:17, 0.00, ug/m3,01-AUG-2018,12:34:56, 0.00, ug/m3,01-AUG-2018,12:35:49, 0.00, ug/m3,01-AUG-2018,12:36:17, 0.00, ug/m3,01-AUG-2018,12:38:50, 0.00, ug/m3,01-AUG-2018,12:39:29, 0.00, ug/m3,01-AUG-2018,12:39:59, 0.00, ug/m3,01-AUG-2018,12:40:31, 0.00, ug/m3,01-AUG-2018,12:41:18, 0.00, ug/m3,

Island AcademyDate Time Result/Units01-AUG-2018,13:15:36, 0.00, ug/m3,01-AUG-2018,13:16:05, 0.00, ug/m3,01-AUG-2018,13:16:36, 0.00, ug/m3,01-AUG-2018,13:17:12, 0.00, ug/m3,01-AUG-2018,13:17:40, 0.00, ug/m3,01-AUG-2018,13:18:14, 0.00, ug/m3,01-AUG-2018,13:18:46, 0.00, ug/m3,01-AUG-2018,13:19:47, 3.48, ug/m3,01-AUG-2018,13:20:27, 0.00, ug/m3,01-AUG-2018,13:21:24, 0.00, ug/m3,01-AUG-2018,13:21:59, 0.00, ug/m3,01-AUG-2018,13:23:00, 0.00, ug/m3,01-AUG-2018,13:23:30, 1.33, ug/m3,01-AUG-2018,13:24:02, 0.51, ug/m3,01-AUG-2018,13:24:43, 0.00, ug/m3,

Beaufort Middle SchoolDate Time Result/Units01-AUG-2018,14:02:25, 0.00, ug/m3,01-AUG-2018,14:03:00, 0.00, ug/m3,01-AUG-2018,14:03:23, 0.00, ug/m3,01-AUG-2018,14:04:34, 0.00, ug/m3,01-AUG-2018,14:05:03, 0.00, ug/m3,01-AUG-2018,14:05:33, 0.00, ug/m3,01-AUG-2018,14:05:57, 0.00, ug/m3,01-AUG-2018,14:06:22, 0.00, ug/m3,01-AUG-2018,14:06:51, 0.00, ug/m3,01-AUG-2018,14:07:23, 0.00, ug/m3,01-AUG-2018,14:07:58, 0.51, ug/m3,01-AUG-2018,14:08:55, 0.00, ug/m3,01-AUG-2018,14:09:17, 1.23, ug/m3,01-AUG-2018,14:09:54, 0.53, ug/m3,01-AUG-2018,14:10:48, 0.00, ug/m3,01-AUG-2018,14:11:46, 1.77, ug/m3,01-AUG-2018,14:13:01, 0.00, ug/m3,01-AUG-2018,14:14:10, 0.00, ug/m3,01-AUG-2018,14:15:02, 0.00, ug/m3,01-AUG-2018,14:16:12, 0.00, ug/m3,01-AUG-2018,14:16:40, 0.00, ug/m3,01-AUG-2018,14:18:00, 0.00, ug/m3,01-AUG-2018,14:19:13, 0.00, ug/m3,01-AUG-2018,14:19:50, 0.00, ug/m3,01-AUG-2018,14:21:42, 0.00, ug/m3,01-AUG-2018,14:22:50, 0.00, ug/m3,

Jerome Model: J405-0007 Serial Number: 405-00952

HVAC SYSTEM OFF FOR AT LEAST 12HOURSAugust 2, 2018 - MorningIsland Academy (HVAC REMAINED INOPERATION)Date Time Result/Units02-AUG-2018, 06:56:26, 0.00, ug/m3,02-AUG-2018,08:02:23, 0.00, ug/m3,02-AUG-2018,08:02:45, 0.00, ug/m3,02-AUG-2018,08:03:03, 0.00, ug/m3,02-AUG-2018,08:17:47, 0.00, ug/m3,02-AUG-2018,08:20:11, 0.00, ug/m3,02-AUG-2018,08:21:54, 0.00, ug/m3,02-AUG-2018,08:22:46, 0.00, ug/m3,02-AUG-2018,08:23:23, 0.00, ug/m3,02-AUG-2018,08:24:11, 0.00, ug/m3,02-AUG-2018,08:25:53, 0.00, ug/m3,02-AUG-2018,08:26:22, 0.00, ug/m3,02-AUG-2018,08:26:47, 0.00, ug/m3,02-AUG-2018,08:27:14, 0.00, ug/m3,

ROBERT SMALLS ACADEMYDate Time Result/Units02-AUG-2018,08:51:30, 1.65, ug/m3,02-AUG-2018,08:51:57, 2.35, ug/m3,02-AUG-2018,08:52:22, 1.78, ug/m3,02-AUG-2018,08:52:51, 1.99, ug/m3,02-AUG-2018,08:53:16, 1.66, ug/m3,02-AUG-2018,08:53:48, 1.87, ug/m3,02-AUG-2018,08:54:24, 1.51, ug/m3,02-AUG-2018,08:55:08, 2.04, ug/m3,02-AUG-2018,08:56:10, 1.77, ug/m3,

Date Time Result/Units02-AUG-2018,08:56:59, 0.00, ug/m3,02-AUG-2018,08:58:34, 0.88, ug/m3,02-AUG-2018,08:59:09, 0.63, ug/m3,02-AUG-2018,08:59:39, 1.51, ug/m3,02-AUG-2018,09:00:07, 1.61, ug/m3,02-AUG-2018,09:00:56, 1.21, ug/m3,02-AUG-2018,09:01:50, 0.00, ug/m3,02-AUG-2018,09:02:33, 1.04, ug/m3,02-AUG-2018,09:05:11, 4.40, ug/m3,02-AUG-2018,09:05:45, 2.31,ug/m3, STAGE02-AUG-2018,09:11:20, 0.63, ug/m3,02-AUG-2018,09:12:06, 0.00, ug/m3, HALL02-AUG-2018,09:12:44, 0.00, ug/m3,02-AUG-2018,09:13:18, 0.00, ug/m3,

BEAUFORT MIDDLE SCHOOLDate Time Result/Units02-AUG-2018,10:03:08, 2.32, ug/m3,02-AUG-2018,10:03:37, 2.66, ug/m3,02-AUG-2018,10:04:10, 2.50, ug/m3,02-AUG-2018,10:04:39, 2.58, ug/m3,02-AUG-2018,10:05:12, 2.45, ug/m3,02-AUG-2018,10:05:55, 2.42, ug/m3,02-AUG-2018,10:06:27, 2.88, ug/m3,02-AUG-2018,10:07:34, 3.26, ug/m3,02-AUG-2018,10:08:07, 2.65, ug/m3,02-AUG-2018,10:08:50, 1.47, ug/m3,02-AUG-2018,10:10:14, 0.00, ug/m3,

Jerome Model: J405-0007 Serial Number: 405-00952Mercury Testing after the HVAC was turned back on.Testing was performed approximately 2 ½ hours afterthe HVAC was turned on.August 2, 2018 - AfternoonBEAUFORT MIDDLE SCHOOLDate Time Result/Units02-AUG-2018,12:13:34, 0.00, ug/m3,02-AUG-2018,13:07:17, 0.00, ug/m3,02-AUG-2018,13:07:53, 0.00, ug/m3,02-AUG-2018,13:08:21, 0.00, ug/m3,02-AUG-2018,13:09:51, 1.68, ug/m3,02-AUG-2018,13:10:18, 1.80, ug/m3,02-AUG-2018,13:10:45, 1.92, ug/m3,02-AUG-2018,13:11:16, 1.81, ug/m3,02-AUG-2018,13:11:41, 1.81, ug/m3,02-AUG-2018,13:12:10, 1.80, ug/m3,02-AUG-2018,13:12:41, 1.76, ug/m3,02-AUG-2018,13:13:22, 1.41, ug/m3,02-AUG-2018,13:13:54, 1.45, ug/m3,02-AUG-2018,13:14:36, 1.30, ug/m3,02-AUG-2018,13:15:14, 1.48, ug/m3,02-AUG-2018,13:15:46, 1.47, ug/m3,02-AUG-2018,13:18:25, 1.21, ug/m3,02-AUG-2018,13:19:11, 0.00, ug/m3,02-AUG-2018,13:19:56, 1.27, ug/m3,02-AUG-2018,13:20:28, 1.44, ug/m3,02-AUG-2018,13:20:57, 1.46, ug/m3,02-AUG-2018,13:21:38, 1.27, ug/m3,02-AUG-2018,13:22:01, 2.02, ug/m3,02-AUG-2018,13:25:00, 1.16, ug/m3,02-AUG-2018,13:25:39, 1.27, ug/m3,02-AUG-2018,13:26:10, 1.30, ug/m3,02-AUG-2018,13:26:39, 1.41, ug/m3,

Date Time Result/Units02-AUG-2018,13:28:47, 0.00, ug/m3,02-AUG-2018,13:29:31, 1.26, ug/m3,02-AUG-2018,13:30:38, 1.33, ug/m3,02-AUG-2018,13:31:27, 1.17, ug/m3,02-AUG-2018,13:32:06, 1.18, ug/m3,02-AUG-2018,13:32:36, 1.09, ug/m3,02-AUG-2018,13:33:07, 1.21, ug/m3,02-AUG-2018,13:33:41, 1.06, ug/m3,02-AUG-2018,13:34:06, 1.13, ug/m3,02-AUG-2018,13:35:08, 0.00, ug/m3,02-AUG-2018,13:35:44, 0.99, ug/m3,02-AUG-2018,13:36:12, 1.40, ug/m3,02-AUG-2018,13:36:46, 1.33, ug/m3,02-AUG-2018,13:44:25, 0.56, ug/m3,02-AUG-2018,13:44:52, 0.84, ug/m3,02-AUG-2018,13:46:22, 0.74, ug/m3,02-AUG-2018,13:46:54, 1.02, ug/m3,02-AUG-2018,13:47:23, 0.93, ug/m3,02-AUG-2018,13:47:55, 1.05, ug/m3,02-AUG-2018,13:48:22, 1.09, ug/m3,02-AUG-2018,13:49:00, 0.91, ug/m3,

ROBERT SMALLS ACADEMYDate Time Result/Units02-AUG-2018,14:20:40, 0.00, ug/m3,02-AUG-2018,14:21:06, 0.00, ug/m3,02-AUG-2018,14:21:33, 0.00, ug/m3,02-AUG-2018,14:23:44, 0.61, ug/m3,02-AUG-2018,14:24:09, 0.99, ug/m3,02-AUG-2018,14:24:37, 1.12, ug/m3,02-AUG-2018,14:25:13, 1.07, ug/m3,02-AUG-2018,14:25:37, 1.26, ug/m3,02-AUG-2018,14:26:02, 1.13, ug/m3,02-AUG-2018,14:26:30, 1.05, ug/m3,02-AUG-2018,14:27:02, 0.94, ug/m3,02-AUG-2018,14:27:30, 0.89, ug/m3,02-AUG-2018,14:28:04, 0.93, ug/m3,02-AUG-2018,14:28:37, 1.03, ug/m3,02-AUG-2018,14:29:09, 1.05, ug/m3,02-AUG-2018,14:29:41, 0.94, ug/m3,02-AUG-2018,14:30:09, 1.07, ug/m3,02-AUG-2018,14:30:37, 1.03, ug/m3,02-AUG-2018,14:31:03, 0.64, ug/m3,02-AUG-2018,14:31:28, 1.06, ug/m3,02-AUG-2018,14:31:50, 1.08, ug/m3,

Date Time Result/Units02-AUG-2018,14:32:11, 1.18, ug/m3,02-AUG-2018,14:33:01, 0.00, ug/m3,02-AUG-2018,14:33:25, 0.00, ug/m3,02-AUG-2018,14:33:54, 1.12, ug/m3,02-AUG-2018,14:36:56, 0.00, ug/m3,02-AUG-2018,14:37:19, 0.00, ug/m3,02-AUG-2018,14:37:43, 0.69, ug/m3,02-AUG-2018,14:38:08, 0.76, ug/m3,02-AUG-2018,14:38:45, 0.69, ug/m3,02-AUG-2018,14:39:17, 0.84, ug/m3,02-AUG-2018,14:39:47, 1.07, ug/m3,02-AUG-2018,14:40:13, 0.83, ug/m3,02-AUG-2018,14:40:45, 0.68, ug/m3,02-AUG-2018,14:41:27, 0.51, ug/m3,02-AUG-2018,14:47:57, 0.00, ug/m3,02-AUG-2018,14:48:34, 0.00, ug/m3,02-AUG-2018,14:49:17, 0.00, ug/m3,02-AUG-2018,14:49:44, 0.64, ug/m3,02-AUG-2018,14:50:11, 0.00, ug/m3,02-AUG-2018,14:50:40, 0.00, ug/m3,02-AUG-2018,14:52:16, 0.00, ug/m3,

APPENDIX II

1

Environmental and Occupational Health Sciences Institute

Michael Gochfeld [email protected]

848‐445‐6093 March 1, 2017 Mary Ann Bell Superintendent of Schools Burlington Township Schools Board of Education 700 Jacksonville Road PO Box 428 Burlington, NJ 08016 [email protected] Dear Ms. Bell: I was pleased to meet with you, your associates, and Dr. Lynch to discuss risks from elemental mercury emanating from gym flooring. I appreciate your proactive stance for protecting the health of employees and children, and I have prepared this letter to capture the main features of our discussion of mercury exposure and risks and provide recommendations. This is a complex situation and I have tried, as Dr. Lynch suggested, to put in order and explain the various levels used in or derived from risk assessments leading to various guidance documents and reference levels. In addition to his work measuring mercury air levels and advising on ventilation and work specifications, Dr.Lynch has assembled an array of mercury in air levels proposed by various agencies as reference levels or guidelines. I have arranged these in Table 1, and I will comment on these both from the top down and the bottom up. I must emphasize that there is not a single bright line below which all is safe and above which it is unsafe. All values in the table below are provided as micrograms of mercury per cubic meter of air (µg/m3).

1 µg = 0.001 mg = 1,000 ng

It is important to recognize that some guidelines are based on protecting the general public, including susceptible individuals, assuming they are exposed continuously 24 hours/day for 7 days a week throughout the year. These reference values are therefore protective of teachers (40 hr/week exposure) and school children (up to 16 hrs/week) who are exposed for shorter periods of time.

2

Also the occupational health criteria from OSHA, NIOSH, and California‐OSHA assume a 25‐30 year working life and the various residential scenarios assume anywhere between 40 and 70 year lifetime exposure. Recognizing that the mercury has been present in the past, the decision at hand concerns 4‐5 additional months of exposure, and whether the mercury concentrations in air in the gym can be maintained at some low level which does not pose harm to adults or children. This letter addresses the appropriate “levels”. Background on Risk Assessment. Risk assessments are done separately for cancer and for non‐cancer endpoints. Despite several highly exposed occupational cohorts (including historic exposures > 100 µg/m3, the evidence indicates that elemental mercury does not cause cancer in humans. Therefore the non‐cancer risk assessment approach is followed with neurotoxic effects as the sensitive endpoints. The general approach to estimating and/or managing non‐cancer risk is to identify one or more studies that identify either a No Observed Adverse Effect Level (NOAEL) or a Lowest Observed Adverse Effect Level (LOAEL). It is preferable if such studies have been done with humans (usually workplace groups), but animal studies can be used. The NOAEL or LOAEL are then divided by a series of uncertainty factors (UFs) to identify some allowable or reference level. Agencies have some leeway in the assumptions they make to identify appropriate uncertainty factors, hence the variability in the published reference values. As a disclaimer, I support, advocate, practice, and teach this general approach to estimating risks, imperfect as they are. I provide some definitions for terms discussed below.

Reference Concentration Definition: An estimate (with uncertainty spanning perhaps an order of magnitude) of a continuous inhalation exposure to the human population (including sensitive subgroups) that is likely to be without an appreciable risk of deleterious effects during a lifetime. It can be derived from a NOAEL, LOAEL, or benchmark concentration, with uncertainty factors generally applied to reflect limitations of the data used. Generally used in EPA's noncancer health risk assessments. No observed adverse effect level (NOAEL): In studies with more than one dose or exposure level, the lowest non‐zero dose at which no adverse effect occurs. This is usually the starting point for a non‐cancer risk assessment calculation. Lowest observed adverse effect level (LOAEL): In studies with more than one dose or exposure level, the lowest dose at which some adverse effect occurs. May be used as basis for risk assessment, if there is no NOAEL. Adjusted LOAEL: Since the human LOAEL are based on occupational exposures for 40 hrs/week, EPA uses an ‘Adjusted LOAEL’ taking into account the longer exposure period for non‐occupational situations, such as residential. Using the LOAEL of 25 µg/m3 EPA arrives at an adjusted LOAEL of 9 µg/m3 which is the basis of its Reference Concentration. Uncertainty Factors (UF): Factors used to derive a reference level. For animal studies a UF=10 is used for interspecific difference. If there is only a LOAEL and no NOAEL then a UF=10 is used. UFs ranging from 3 to 10 are used to adjust for short duration studies and for intraspecific variability to protect susceptible individuals. UFs are multiplicative. Interspecific UF: Used to extrapolate from animal toxicity to estimate human response to mercury. Typical UF=10 Intraspecific: UF Used to account for variation among humans in response to mercury. Typical UF=10.

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Air Levels of Mercury Table 1 summarizes various guideline and risk estimations relevant to airborne mercury in schools. The left hand side of the table represents the RISK calculations, and the right hand side represents CRITERIA or REFERENCE VALUES. Several school action levels are suggested in red font in the Explanation column. Table 1 Summarizes Health and risk values and various criteria, reference values , guidelines or action levels that can be used to identify appropriate air concentrations for protecting teachers and children in schools. The values are arrayed from high to low and are expressed as µg/m3.

Health and Risk Assessments Mercury in Air Action Levels

Explanation Definition µg/m3 Definition Explanation

Based on lab exposure of pregnant female rats

Basis for California Acute Reference Exposure Level

1800

100 OSHA Permissible Exposure Limit

Occupational level allowed as an 8 hour time‐weighted average for a 40 hour work week, usually for a 25 yr period

50 NIOSH Recommended Exposure Level

25 CAL OSHA Permissible Exposure Limit

Air level not measured directly but estimated from workers’ blood levels

Neurologic & neurobehavioral findings observed at this level

25 Lowest Observed Adverse Effect Level (LOAEL)

Based on occupational epidemiologic studies of workers

10 ATSDR Action Levela for evacuation or limiting exposure

ATSDR would Close gym until levels fall below 3.0

This is the adjusted LOAEL used by EPA & California

LOAEL adjusted downward to account for >40 hr/wk exposures.

9

4

3‐6 ATSDR level above which sampling of personal belongings impacted by liquid mercury is suggested

Air monitor headspace of contents impacted by liquid mercury when air levels > 6 ug/m3

3 ATSDR Re‐occupancy level

Close gym at 3

1 to 3 ATSDR Acceptable level for commercial places or schools

2.5 In absence of a NOAEL divide the LOAEL of 25 by 10

Based on unadjusted LOAEL as a Gochfeld Recommended Exposure Level” (for 40 hr/week

Basis for California Acute Reference Exposure Level

1.8 Minnesota DoH Short Term (<1 hour) Mercury Vapor Exposure Guideline

1 ATSDR Action Levela

Try to keep mercury levels below ATSDR CDC Action Level of 1

0.75‐0.80 Minnesota Long‐term Exposure Guideline

Adjusted upward from the EPA RfC (for 16 hrs/wk)b

Cumulative UF=3000

California Acute Reference Exposure Level

0.6

Cumulative UF=30

0.3 EPA Reference Concentration

Keep time‐weighted average below this Residential 24/7 exposure; to protect sensitive individuals

5

0.2 ATSDR Minimal Risk Level

Residential 24/7 exposure protects sensitive individuals

Cumulative UF=100

0.09 Suggested alternative California Chronic REL (UF=100)

0.06 California 8 hour Reference Exposure Level

Cumulative UF=300

0.03 California Chronic REL as published Non‐standard UF=300

UF=300 Impairment of neurobehavioral functions in humans

a= Action Level from the “Chemical‐Specific Health Consultation for Joint EPA/ATSDR National Mercury Cleanup Policy Work Group March 22, 2012. https://www.atsdr.cdc.gov/emergency_response/action_levels_for_elemental_mercury_spills_2012.pdf b=Minnesota Dept of Health “Long‐term mercury vapor exposure guidelines” to protect gym teachers (40 hrs/week) and children in gym (16 hrs/week). http://www.health.state.mn.us/divs/eh/hazardous/topics/mercury/hgflooringprofguide.html

The EPA Reference Concentration for elemental mercury is listed in the Integrated Risk Information System (IRIS) data base as 0.0003 milligrams/m3 equal to 0.3 µg/m3. This was derived from several studies showing neurologic and neurobehavioral effects at around 25 µg/m3 Because these were occupational epidemiology studies based on a 40 hour work week, and EPA was concerned about protecting the general public, EPA adjusted the 25 µg/m3 downward to 9 µg/m3 as the basis for calculating a reference concentration that would provide protection for the general public beyond the 40 hour work week. California Chronic Reference Exposure Level The California Chronic REL of 0.03 µg/m3 has been put forth by the NJ Work Environment Council as a guideline or action air level to support decisions. I examined how California arrived at this value which is an order of magnitude lower than the EPA RfC. The methods are compared in Table 2. EPA and California started with the same human health studies yielding a LOAEL of 25 µg/m3.. EPA and California both adjusted this LOAEL down to 9 µg/m3 to accommodate the longer exposure for a residential scenario compared to the 40 hour week. Both EPA and California used UF=10 to adjust for the absence of a NOAEL. Both agencies used a UF=3 to adjust for interindividual variability. Here the methods diverge. California then inserted an additional UF=10 to be ‘protective of children’. California thus incorporated a cumulative UF=300. However, this represents double‐counting since the protection of children is included in the UF for intraspecific variability. This is not a standard risk

6

assessment approach and yields an unrealistic exposure level of 0.03 µg/m3. On the other hand, it is probably realistic to use UF=10 for intraspecific variability, yielding a cumulative UF=100 and resulting in a suggested revised Chronic Reference Exposure Level of 0.09 µg/m3 for protecting the public from continuous exposure. I have indicated this in Tables 1 and 2.

TABLE 2. Comparison of EPA and California risk assessments for mercury: chronic exposure non‐occupational

Environmental Protection Agency California EPA

Same LOAEL from neurobehavioral stuodies

25 µg/m3 25 µg/m3

Time‐adjusted exposure for 24/7 9 µg/m3 9 µg/m3

UF =10 from LOAEL to NOAEL 0.9 µg/m3 0.9 µg/m3

UF=1 for interspecies (not necessary, based on humans)

0.9 µg/m3 0.9 µg/m3

UF=√10 for inter‐individual variability

0.3 µg/m3 0.3 µg/m3

UF=10 for children susceptibility Subsumed under inter‐individual variability

0.03 µg/m3 (see point 4 below)

Reference Concentration=0.3 µg/m3 Cumulative UF=30

Chronic Reference Exposure Level = 0.03 µg/m3 Cumulative UF=300

Suggested Revision of California Chronic Reference Exposure Level

0.09 µg/m3 might be an appropriate level using the UF=10 rather than UF=3 resulting in a Cumulative UF=100

These values are considered protective of susceptible individuals including infants and are based on continuous exposure 24/7 for homebound individuals. These are amply protective of school employees with 40 hr/week and school children with 16 hr/week exposures.

Additional points.

1) The LOAEL of 25 µg/m3 is clearly a neurotoxic level for adults as shown in the studies cited by both EPA and California. It should not be used as an occupational standard. I propose that a level of 2.5 µg/m3 might be appropriate as an 8 hour time‐weighted average for a 40 hour week, to protect workers, including school teachers.

2) School exposures (up to 40 hrs/wk) are lower than the public residential guidelines, hence those guidelines from EPA (RfD) and ATSDR (MRL) are protective of teachers and students

3) ATSDR considered 1 to 3 µg/m3 to be acceptable for school occupancy and conversely once levels have fallen down to 3 µg/m3 re‐occupancy is allowed. This may be acceptable for brief elevations of mercury.

4) The California chronic value of 0.03 µg/m3 is overcorrected since the UF=10 for children susceptibility is already accounted for under the inter‐individual variability UF=3,. The combined UF of 100 rather than 30 would be reasonable, leading to a recommended revised Chronic REL

7

of 0.09 µg/m3 for lifetime exposure at 24/7. [NOTE the UF=3 is shown as the square root of 10 for arcane reasons].

5) The expanded ventilation schedule recommended by Dr. Lynch should be effective at keeping the time‐weighted average exposure levels below 0.3 µg/m3 . and excursions below 1 µg/m3.

Conclusions From this analysis I conclude that for day‐to‐day protectiveness, keeping the time‐weighted average air mercury levels below 0.3 µg/m3 , the EPA Reference Concentration, will adequately protect the teachers and children. No adverse health effects are detected at this level. Excursions up to 1.0 µg/m3, the ATSDR Action Level) would not cause health problems, but should be minimized. It is always desirable to minimize exposure and most of the air levels that Dr. Lynch measured during occupied mode are well below 0.3 µg/m3 . If air levels rise and stay above 3 µg/m3, closing the gym would be recommended. Dr.Lynch has made important recommendations regarding operations of the air handling system to keep mercury concentrations as low as can be reasonably achieved. Over the next 4‐5 months that the floor is in place, these low air levels should not result in adverse health impacts. Please feel free to engage me in further discussion of the risk decisions and risk communication. Sincerely yours,

Michael Gochfeld, MD, PhD Professor Emeritus and Adjunct Professor Rutgers Robert Wood Johnson Medical School and School of Public Health

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