HEALTH CONSULTATION
CABOT-WROUGHT PRODUCTS, DIVISION OF CABOT COPRORATION
(a.k.a. NGK METALS/CABOT BERYLCO, INCORPORATED)
MUHLENBERG, BERKS COUNTY, PENNSYLVANIA
BACKGROUND AND STATEMENT OF ISSUES
ATSDR has been asked to evaluate additional ambient air data presented in a document released by the Environmental Protection Agency (EPA) in June 1997 [1]. The purpose of this consult is to address the public health significance of the data generated by the NGK in-house analytical method and the NGK contractor analytical method.
NGK Metals Corporation (NGK) is a 65 acre facility located in Muhlenberg Township, Berks County, Pennsylvania, approximately 4 miles north of Reading. Industrial activities began prior to 1935 and have continued through the present. Current operations include the production of beryllium alloys and the chemical and mechanical cleaning of beryllium alloys. Past operations included: extraction of beryllium hydroxide from beryl ore until 1965; and casting, heat treatment, and rolling of beryllium alloys, which was discontinued in 1992. Ownership of this facility has changed several times. The present owners obtained the facility in 1986. It is operated today as a subsidiary of NGK Insulators Ltd. of Nagoya, Japan.
The Agency for Toxic Substances and Disease Registry (ATSDR) released a Petitioned Public Health Assessment on June 27, 1995. The conclusions drawn from the investigation were that the concentrations of contaminants in the environmental media (air, water, soil) did not present a public health hazard based on current levels of contaminants detected [2]. However, the site was classified 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. This system monitors ambient air beryllium under the National Emission Standards for Hazardous Air Pollutants (NESHAP) regulations. Historical data from NGK (provided to EPA Region III) gives information on two monitors. The NGK-operated ambient air monitor (Y-1) has filters analyzed in-house by the NGK laboratory. It is co-located with the NGK-operated air monitor (R-1) which has filters analyzed by a contractor. The data indicate that the Y-1 air monitor had consistently higher levels of beryllium than the R-1 monitor [1] (see Appendix A). The EPA report assessed whether the NGK contractor's analytic method, approved by the EPA, was as effective in measuring total beryllium concentrations in ambient air as the NGK in-house method [1]. Direct correlation of values was not made owing to the very different filter types used, monitor manufacture differences, differing analytical methods employed for filter analysis, and variation in quality assurance practices in both monitor operation and analytical method. It was concluded that the analytic method employed by the NGK contractor on filters was not as rigorous as possible. However, no exceedances of National Emission Standards for Hazardous Air Pollutants (NESHAP) standards were detected by one monitor and not the other [1].
The historical data provided to ATSDR cites weekly averages of beryllium levels in off-site
ambient air for monitors Y-1 and R-1 from December 27, 1988 through July 5, 1994 [Appendix
A]. The off-site standard for beryllium under NESHAP is 0.01 ug/m3 as a monthly average. The
5 weeks from May 23 - June 27, 1989 is the only extended period during which the average
concentration of beryllium exceeds 0.01 ug/m3. Levels were also above the NESHAP off-site
standard at both monitors for the week of August 15 - 22, 1989. The week of June 6-13 recorded
the 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 the
week 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. | ||||
| YEAR (1989) |
Y-1a (in-house) |
R-1b |
Comparison Value (CREG) ug/m3 |
NESHAPc off-site standard ug/m3 |
| 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 are located across the street from the southern border of NGK and an active railroad line passes along its' eastern boundry [2]. The total number of persons living within a 1 mile radius of the NGK site is estimated at 4,927 [2]. The population in this radius is predominantly white (98%) with a sizeable percentage of persons greater than 44 years of age (49%). Children less than 15 years of age account for 13% of the total population. Women of childbearing age (15-44 years) are estimated at 18% of the population. Approximately 80% of the homes are owner occupied. The nearest residences are within 50 to 100 yards south of the NGK site.
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