Document Gax1z3EKaj45Eq0606RJ0Vbr

i t . JUU .12-12- 0 . 5-uaPM : HAHK1.NS & PARNELL- Vittorio K. Argcnto, Ph.D., P.E. Enrirowntnlal Engineering Scrrica 1216 N. Cedar Ridge Duncanville, Texai 75116 713 863 56413/ 6 The Recon Environmental Report, Air Sampling Protocol Document, volumes l, 2, 3, and 4 were read and reviewed. As a result of this reading and review of this document, I have come to the following conclusions: 1. The roofing materials involved in this project were products of the Bird Incorporated roofing company. 2. The roofing removal procedures were consistent with the techniques used by roofers in the removal of roofing materials from an existing structure. 3. The personal and area monitoring results were an accurate indication of a worker's exposure to airborne asbestos fibers and area concentrations of airborne asbestos fibers. 4. The sample collection and analysis protocols for both Phase Contrast Microscopy (PCM) and Transmission Electron Microscopy (TEM) represented currently accepted practices and procedures for the determination of worker exposure to airborne asbestos fibers and area concentrations of airborne asbestos fibers- 5. The documentation in the report was sufficient to allow worker time weighted average exposures to airborne fibers by PCM, and airborne asbestos fibers by TEM, to be calculated for each day the worker was involved with the project. 6. The documentation in the report was sufficient to allow the maximum possible eight-hour time weighted average (TWA) worker exposures to airborne fibers by PCM, and airborne asbestos fibers by TEM, to be calculated for each day the worker was involved with the project. 7. The worker 8-hour time weighted average fiber (PCM) and asbestos (TEM) exposures were well below the current worker protection standards of the Occupational Safety and Health Administration of the U.S. Department of Labor (OSHA). 8. The current OSHA worker asbestos exposure standard, established in 1994, is more stringent than any previous asbestos exposure standard established by OSHA. Therefore, exposures of roofers to airborne asbestos fibers from similar roofing removal operations conducted prior to 1994 would have been an even smaller fraction of the existing acceptable asbestos exposure standard. 9. Based on these results and conclusions, it is my opinion, to a reasonable degree of scientific certainty, that removal of Bird Incorporated roofs, conducted in a manner similar to the techniques and practices identified in the Recon Environmental report (#W50276), did not pose a health threat to the roofing workers from exposure to asbestos fibers and that the Bird Incorporated roofing product was a safe product to use. Pape I BIRD  JWU -12-12- U : 5-09PM : HANKINS & PARNELL- 713 865 5641:* 4/ 6 Vittorio K. Argento, Pb.D., PJ. Environmental Engineering Services 1226 N. Cedar Ridge Duncanville, Texas 75116 The U.S. Occupational Safety and Health Administration revised the permissible exposure limit (PEL) for airborne asbestos fibers, effective October 11,1994, to 0,10 fibers per cubic centimeter (f/cc) of air, based on an 8-hour rime weighted average (8-hour TWA). On September 14, 1988, OSHA established an excursion limit, or short term exposure limit (STEL) for asbestos fibers of 1.0 f/cc, based on a 30 minute averaging time. Prior OSHA asbestos exposure standards were: TABLE 1 YEAR 1986 1976 1972 Asbestos Permissible Exposure Limit 0.2 f/cc, 8-hour TWA 2.0 f/cc 8-hour TWA 5.0 f/cc 8-hour TWA Based on the personal monitoring data provided in the Recon report, the following worker time weighted average exposures and maximum possible 8-hour time weighted average exposures were calculated. Since none of the worker's monitoring data indicated that they worked an 8-hour day (most worked approximately 9 to 11.5 hours each day), the workers daily time weighted average exposure for the entire work day was calculated. These exposures were then converted to the maximum 8-hour time weighted average the worker could have experienced each day. The maximum possible 8-hour time weighted average exposures could then be compared with the OSHA permissible exposure limit for asbestos. These exposure calculations are tabulated in Table 2, on the next page. The asbestos fiber exposures, established by the TEM analyses were calculated for each workers daily exposure. These exposures arc shown in Table 3. Page 2 BIRD _i_w U! Llf.JUU .12-12- 0 ; 5-U3PM : HAKKINS & PARNELL- Vittorio K. Argtnto, Ph.D., P.E. , Environmental Engineering Services IZZS N- Cedkr Ridge Dnocantilk, Tens 75116 713 865 5641 ^ 5/ 6 TABLE 2 WORKER DAILY TIME WEIGHTED AVERAGE EXPOSURES AND MAXIMUM POSSIBLE 8-HOUR TIME WEIGHTED AVERAGE EXPOSURES Date Worker 6-27-95 Lewis Delvin 6-27-95 Marshall Richards 6-21-95 Antonio Ramos 6-27-95 Edgar Ramos 6-27-95 John Lcja 6-27-95 Gary Berrios 6-27-95 Qvidio Baralaona 6-21-95 Ercnsto Delgado C. 6-28-95 Lewis Delvin 6-28-95 Marshall Richards 6-28-95 Antonio Ramos 6-28-95 Edgar Ramos 6-28-95 John Leja 6-28-95 Gary Berrios 6-28-95 Ercnsto Delgado 6-29-95 6-29-95 6-29-95 6-29-95 6-29-95 6-29-95 6-29-95 Lewis Delvin Marshall Richards Antonio Ramos Edgar Ramos John Leja Gary Berrios Erensto Delgado Daily Time Weighted Average Exposure 0.040 f/cc 0.035 f/cc 0.011 f/cc 0.006 f/cc 0.012 f/cc 0.008 f/cc 0.018 f/cc 0.013 f/cc 0.023 f/cc 0.016 f/cc 0.016 f/cc 0.022 f/cc 0.038 f/cc 0.019 f/cc 0.018 f/cc 0.008 f/cc 0.011 f/cc 0.016 f/cc 0.013 f/cc 0.016 f/cc 0.007 f/cc 0.019 f/cc Maximum Passible 8-Hour TWA 0.046 f/cc 0.040 f/cc 0.012 f/cc 0.006 f/cc 0.013 f/cc 0.010 f/cc .0.009 f/cc 0.006 f/cc 0.028 f/cc 0.020 f/cc' 0.020 f/cc 0.026 f/cc 0.020 f/cc 0.023 f/cc 0.021 f/cc 0.012 f/cc 0.016 f/cc 0.024 f/cc 0.019 f/cc 0.023 f/cc 0.011 f/cc 0.014 f/cc Page 3 BIRD 015009 uli,JUU .11!-12- 0 5 09PM : HAM I NS & PARNELL- Vittorio K. Argcnto, Ph-D., P.E. Environment*! Engineering Services' 1226 N.Ced.t Ridge Duncanville, Texas 7SlXfi 713 865 -56 J1 = 6/ 6 TABLE 3 WORKER DAILY TIME WEIGHTED AVERAGE EXPOSURES TO ASBESTOS FIBERS BASED ON TEM COUNTS OF ASBESTOS STRUCTURES Date Worker 6-27-95 Lewis Delvin 6-27-95 Marshall Richards 6-27-95 Antonio Ramos 6-27-95 Edgar Ramos 6-27-95 John Leja 6-27-95 Gary Berrios 6-27-95 Ovtdio Baralaona c. 6-27-95 Erensto Delgado 6-28-95 Lewis Delvin 6-28-95 Marshall Richards 6-28-95 Antonio Ramos 6-28-95 Edgar Ramos 6-28-95 John Leja 6-28-95 Gary Berrios 6-28-95 Erensto Delgado Daily Time Weighted Average Exposure To Asbestos Fibers 0.0009 f/cc 0.0000 f/cc 0.0000 f/cc 0.0000 f/cc 0.0000 f/cc 0.0000 f/cc 0.0000 f/cc 0.0000 f/cc 0.0000 f/cc 0.0000 f/cc 0.0083 f/cc 0.0000 f/cc 0.0000 f/cc 0.0000 f/cc 0.0032 f/cc 6-29-95 6-29-95 6-29-95 6-29-95 6:29-9S 6-29-95 6-29-95 Lewis Delvin Marshall Richards Antonio Ramos Edgar Ramos John Leja Gary Berrios Erensto Delgado 0.0000 f/cc 0.0000 f/cc 0.0000 f/cc 0.0017 f/cc 0.0000 f/cc 0.0000 f/cc 0.0000 f/cc Page 4 BIRD 015010 17 BIRD 015006