Lawrence H. Hecker

Heavy Metal Levels in Acculturated and Unacculturated Populations

In the comparison of metals in the hair, blood, and urine of 100 acculturated and 90 unacculturated individuals copper level was found to be the same in both groups. Levels of lead and cadmium were found to be markedly lower in the unacculturated population. Mercury was the same, higher, or lower in the unacculturated population, depending on sex and location. The higher values resulted from levels in men. On the basis of current knowledge, elevated levels may derive from exposure to alkyl mercury.

INTERNAL WALL LOSSES OF PHARMACEUTICAL DUCTS DURING CLOSED-FACE, 37-MM POLYSTYRENE CASSETTE SAMPLING

A current practice for the determination of personal exposures to dusts involves the aspiration of known quantities of air through membrane filters held in 37-mm plastic cassettes. Samples are collected with the cassettes in the closed-face configuration. A major negative bias error has been identified with this sampling procedure for low-level pharmaceutical dusts. For the pharmaceuticals studied, on average, 62% of the active dust collected in each sample was found on the inside surface of the cassette top. Only 22% of the total active ingredient of the dust was found on the filters. The remaining 16% was found on the inside of the cassette bottoms; electrostatic attraction appears to be the reason that pharmaceutical dusts adhere to the inside surface of the cassette. Adherence to the inside surfaces of the polystyrene cassette occurs without regard to the type of material used to seal the two-piece cassette together. The use of shrink wrap versus plastic tape versus using no sealing material had no effect on where or how much of the active ingredient was found on the inside cassette surfaces. Because very little active ingredient was identified in backup cassettes, it is hypothesized that the active ingredient found on the inside of the bottom portion of the cassettes (past the filter and support pad) got there by falling off the filter during filter removal from the cassette prior to analysis. To eliminate both of these errors, an internal cassette extraction procedure was developed that (1) negates the error caused by static charging and (2) eliminates the need for opening the cassettes prior to analysis.(ABSTRACT TRUNCATED AT 250 WORDS)

Simulated Workplace Protection Factor Study of Powered Air-Purifying and Supplied Air Respirators

A study protocol was developed to obtain simulated workplace protection factor (SWPF) data for eleven models of powered air-purifying respirators (PAPRs) and supplied-air respirators (SAR) with hoods and helmets. Respirators were tested in a chamber that allowed the simulation of 12 exercises, including 2 exercises of interest to the pharmaceutical industry. Each respirator was tested by 12 volunteers, and a total of 144 sets of test results were obtained for each device. The testing protocol allowed SWPFs up to 250,000 to be measured (limit of quantification). Median SWPFs for all respirators, except one SAR, were at or above this reporting limit. Lower fifth percentiles were above 100,000, except for one SAR previously noted. An assigned protection factor (APF) was estimated for each respirator by dividing the lower fifth percentile by a safety factor of 25. APFs ranged from 6000-10,000 for PAPRs (including one loose-fitting PAPR) and 3400-10,000 for SARs, with one exception. This SAR had a lower fifth percentile of less than 20 and an estimated APF of 1. Results indicated that most respirators tested could provide a high degree of protection for workers, although one National Institute for Occupational Safety and Health-approved SAR provided minimal, if any, protection. Direct testing in a simulated workplace seems the only method that will assure employers of choosing an adequate SAR. This may be true for other classes of respirators. Furthermore, the historical approach of establishing APFs for classes of respirators, rather than individual models, may not provide adequate protection to the wearer. This is also a serious problem for regulatory agencies seeking to promulgate respirator standard provisions such as APFs for classes of respirators.

GRAVIMETRIC DETERMINATION OF AIRBORNE DUST BY USING A FILTER CARTRIDGE INSIDE A CLOSED-FACE, 37-MM POLYSTYRENE CASSETTE

The current practice for the determination of personal exposures to airborne dusts involves the aspiration of known quantities of air through membrane filters held in filter holders. The two-piece, 37-mm polystyrene cassette is the most typically used filter holder. Two potential major errors exist with filter-based air-sampling methods. The first error is caused by potential sample loss on the inside of the cassette top during the samples collection and shipment back to the laboratory for analysis. A second error is caused by sample loss during the removal of the filter from the cassette prior to analysis. The potential for sample loss creates a third problem that is specific to gravimetric methods. A small linear range exists for gravimetric methods between their limit of quantitation and filter capacity. A new filter cartridge device was developed and evaluated to estimate the concentration of airborne total dusts over a larger linear range while eliminating negative bias errors associated with both s...

Field validation of passive dosimeters for the determination of employee exposures to ethylene oxide in hospital product sterilization facilities

Passive dosimetry has considerable advantages over active sampling for monitoring exposures to ethylene oxide (EtO), including reduced complexity, reduced cost, and increased sample stability. The major disadvantage of these methods is the conflicting data currently being reported in the literature regarding their ability to meet Occupational Safety and Health Administration (OSHA) method accuracy requirements at the 1 ppm permissible exposure limit (PEL). A field validation study was performed to determine the accuracy of three EtO passive dosimeters (3M-3550®, DuPont Pro-tek,® and AMSCO EO-Self-Scan®) and a common active method (Qazi-Ketchum [QK]) as area samples at four unique concentrations inside a hospital products sterilization facility. Collected at each location were 12 dosimeters of each type along with 12 QK tubes and hourly Tedlar® bag grab samples analyzed by gas chromatography with flame ionization detection (GC-FID). To enhance the strength of this study, manufacturers of EtO dosimeters wer...

A SHORT-TERM SOLID SORBENT DETERMINATION OF HYDRAZOIC ACID IN AIR

A sampling and analytical method for the measurement of hydrazoic acid (HN3) at the short-term ceiling limit was developed and validated under both laboratory and field conditions. The HN3 was collected on sodium hydroxide pretreated Orbo 52 silica gel tubes at a sampling flow rate of 1.0 L/min for 15 min. The samples were stored at room temperature until analyzed, and sample stability at 4 weeks was documented. The HN3 was desorbed with distilled water and the eluent was analyzed by high-pressure liquid chromatography with ultraviolet detection (210 nm). The desorption efficiency of HN3 from the Orbo 52 tubes was determined to be 96% over the 15-min time-weighted average concentrations of 0.025, 0.1, and 1.0 ppm HN3. The method limit of detection was determined to be 0.01 ppm. The coefficient of variation of the combined sampling and analytical method was 8.7%. A 2% method bias and total method accuracy of ±19% were estimated. The field validation of the method occurred over the concentration ranges of <...

Gaseous Emissions from Unregulated Mobile Sources

The impact of gaseous exhaust emissions is determined for the following categories of mobile sources which are currently not covered by national emission regulations; merchant vessels, locomotives, lawn and garden implement, snowmobiles, outboard motors, transport refrigeration units, and helicopters. Mass emission rates of each category are tabulated and compared to other emissions from both mobile and stationary sources in selected Air Quality Control Regions. Also, projections are made as to the expected increase of emissions from each source category through 1990. The results show that in the near future some categories of mobile sources will be contributing substantial amounts of pollutants, on a mass basis, in regions with critical air pollution problems. As stricter emission standards on regulated sources continue to be implemented, the relative significance of these unregulated sources will increase. The major conclusion is that broad generalizations as to the amounts of air pollution contributed by these unregulated mobile sources nationwide may be grossly misleading. The only effective way to assess their impact is on a region-by-region basis. To this end, generalized computer programs are developed which permit the estimation of each categorys present and future mass emission rates in any Air Quality Control Region in the country.

DEVELOPMENT AND VALIDATION OF A PROTOCOL FOR FIELD VALIDATION OF PASSIVE DOSIMETERS FOR ETHYLENE OXIDE EXCURSION LIMIT MONITORING

An exposure and analysis protocol is described for the field validation of passive dosimeters for ethylene oxide (EtO) excursion limit monitoring. The protocol calls for the use of a field exposure chamber with concurrent sampling using Tedlar air-sampling bags. The bags are analyzed immediately after sampling by gas chromatography with flame ionization detection (GC-FID). The chamber design allows all monitors to be exposed for the exact same time in the field. The sampling and analysis procedure not only determines the actual concentration of EtO present during the monitors exposure but estimates if concentrations of EtO vary from point to point in the monitor array during the exposure. In chamber operation, the accuracy of the standard generator used to calibrate the GC-FID was independently verified in the field by the standard additions method. The sampling bias of the sampling train was determined to be -3.5% in the 2.4 ppm to 14.3 ppm concentration range. To estimate the stability of collected EtO samples in Tedlar bags, the rate of EtO loss in the bags was determined to be 0.011 ppm/hr at 2.57 ppm and 0.066 ppm/hr at 8.07 ppm. Sampling bias of the passive methods by additional EtO exposure of the monitors in the closed chamber after sampling and during purging was determined to be +1.5%. The Tedlar bag sampling method with subsequent GC-FID determination demonstrated a coefficient of variation of 1.8% at 2.43 ppm.

The effect of methoxychlor on periphyton under natural conditions

This research was conducted at the Michigan Department of Natural Resources research station located near Saline, Michigan, U.S.A., during May and June of 1975. Koch-Warner Creek, which is spring fed, supplies water that is passed from a reservior to a duplicate series of three outdoor channels. Each section is 36.6 meters in length, 5.4 meters in width, and varies in depth from 0.3 to i.i meters.

Generation of Ethylene Oxide Permissible Exposure Limit Data with On-Site Sample Analysis Using the EO Self-ScanTM Passive Monitor

A sampling and analytical method is presented for the use of EO Self-ScanTM dosimeters for the determination of ethylene oxide permissible exposure limit (PEL) data. Analysis and report generation are performed on-site by trained personnel. A computer program for performing the calculations required to obtain accurate exposure data is described. The computer program is written in Microsoft BASICATM for use on MS-DOS based systems. The advantages and disadvantages of this method are described in detail.