CABOT-WROUGHT PRODUCTS, DIVISION OF CABOT COPRORATION
(a.k.a. NGK METALS/CABOT BERYLCO, INCORPORATED)
MUHLENBERG, BERKS COUNTY, PENNSYLVANIA
ATSDR has been asked to evaluate additional ambient air data presented in a document releasedby the Environmental Protection Agency (EPA) in June 1997 . The purpose of this consult isto address the public health significance of the data generated by the NGK in-house analyticalmethod and the NGK contractor analytical method.
NGK Metals Corporation (NGK) is a 65 acre facility located in Muhlenberg Township, BerksCounty, Pennsylvania, approximately 4 miles north of Reading. Industrial activities began prior to1935 and have continued through the present. Current operations include the production ofberyllium alloys and the chemical and mechanical cleaning of beryllium alloys. Past operationsincluded: extraction of beryllium hydroxide from beryl ore until 1965; and casting, heattreatment, and rolling of beryllium alloys, which was discontinued in 1992. Ownership of thisfacility has changed several times. The present owners obtained the facility in 1986. It isoperated today as a subsidiary of NGK Insulators Ltd. of Nagoya, Japan.
The Agency for Toxic Substances and Disease Registry (ATSDR) released a Petitioned PublicHealth Assessment on June 27, 1995. The conclusions drawn from the investigation were that theconcentrations of contaminants in the environmental media (air, water, soil) did not present apublic health hazard based on current levels of contaminants detected . However, the site wasclassified as an Indeterminate Public Health Hazard due to the lack of data for air (prior to 1979)and groundwater (prior to 1990). ATSDR was not able to draw any conclusions on whether past exposures of public health significance had occurred via these two media.
NGK maintains an ambient air quality monitoring system in the area surrounding its facility. Thissystem monitors ambient air beryllium under the National Emission Standards for Hazardous AirPollutants (NESHAP) regulations. Historical data from NGK (provided to EPA Region III) givesinformation on two monitors. The NGK-operated ambient air monitor (Y-1) has filters analyzedin-house by the NGK laboratory. It is co-located with the NGK-operated air monitor (R-1) whichhas filters analyzed by a contractor. The data indicate that the Y-1 air monitor had consistentlyhigher levels of beryllium than the R-1 monitor  (see Appendix A). The EPA report assessedwhether the NGK contractor's analytic method, approved by the EPA, was as effective inmeasuring total beryllium concentrations in ambient air as the NGK in-house method . Directcorrelation of values was not made owing to the very different filter types used, monitormanufacture differences, differing analytical methods employed for filter analysis, and variation inquality assurance practices in both monitor operation and analytical method. It was concludedthat the analytic method employed by the NGK contractor on filters was not as rigorous aspossible. However, no exceedances of National Emission Standards for Hazardous Air Pollutants(NESHAP) standards were detected by one monitor and not the other .
The historical data provided to ATSDR cites weekly averages of beryllium levels in off-siteambient air for monitors Y-1 and R-1 from December 27, 1988 through July 5, 1994 [AppendixA]. The off-site standard for beryllium under NESHAP is 0.01 ug/m3 as a monthly average. The5 weeks from May 23 - June 27, 1989 is the only extended period during which the averageconcentration of beryllium exceeds 0.01 ug/m3. Levels were also above the NESHAP off-sitestandard at both monitors for the week of August 15 - 22, 1989. The week of June 6-13 recordedthe highest beryllium levels, 0.11 ug/m3 and 0.08 ug/m3 for monitors Y-1 and R-1 respectively. Table 1 lists the weekly ambient air averages of beryllium for this 5 week time frame and for theweek of August 15 - 22, 1989.
|Table 1. Weekly averages of beryllium levels (ug/m3) in off-site ambient air as measured by NGK in-house and NGK contractor monitors for specified period in 1989.|
|May 23 - May 30||0.02||0.02||0.0004||0.01|
|May 30 - June 6||0.04||0.04||0.0004||0.01|
|June 6 - June 13||0.11||0.08||0.0004||0.01|
|June 13 - June 20||0.04||0.04||0.0004||0.01|
|June 20 - June 27||0.03||0.02||0.0004||0.01|
|August 15 - August 22||0.04||0.03||0.0004||0.01|
a Analysis of ambient air monitor by NGK in-house method
b Analysis of ambient air monitor by NGK contractor method
c National Emission Standards for Hazardous Air Pollutants (off-site standard), based on 30 day average exposure
The area surrounding the NGK site is commercial and residential. Several light industries arelocated across the street from the southern border of NGK and an active railroad line passes alongits' eastern boundry . The total number of persons living within a 1 mile radius of the NGKsite is estimated at 4,927 . The population in this radius is predominantly white (98%) with asizeable percentage of persons greater than 44 years of age (49%). Children less than 15 years ofage account for 13% of the total population. Women of childbearing age (15-44 years) areestimated at 18% of the population. Approximately 80% of the homes are owner occupied. Thenearest residences are within 50 to 100 yards south of the NGK site.