Evaluation of methyl tert-butyl ether (MTBE) as an interference on commercial breath-alcohol analyzers.

Anecdotal reports suggest that high environmental or occupational exposures to the fuel oxygenate methyl tert-butyl ether (MTBE) may result in breath concentrations that are sufficiently elevated to cause a false positive on commercial breath-alcohol analyzers. We evaluated this possibility in vitro by establishing a response curve for simulated breath containing MTBE in ethanol. Two types of breath-alcohol analyzers were evaluated. One analyzer's principle of operation involves in situ wet chemistry (oxidation of ethanol in a potassium dichromate solution) and absorption of visible light. The second instrument uses a combination of infrared absorption and an electrochemical sensor. Both types of instruments are currently used, although the former method represents older technology while the latter method represents newer technology.The percent blood alcohol response curve was evaluated over a breath concentration range thought to be relevant to high-level environmental or occupational exposure (0-361 microg/l). Results indicate that MTBE positively biases the response of the older technology Breathalyzer when evaluated as a single constituent or in combination with ethanol. We conclude that a false positive is possible on this instrument if the MTBE exposure is very high, recent with respect to testing, and occurs in combination with ethanol consumption. The interference can be identified on the older technology instrument by a time dependent post-reading increase in the instrument response that does not occur for ethanol alone. In contrast, the newer technology instrument using infrared and electrochemical detectors did not respond to MTBE at lower levels (0-36 microg/l), and at higher levels (>72 microg/l) the instrument indicated an "interference" or "error". For this instrument, a false positive does not occur even at high MTBE levels in the presence of ethanol.     

The National Ballistics Imaging Comparison (NBIC) project

In response to the guidelines issued by the American Society of Crime Laboratory Directors/Laboratory Accreditation Board (ASCLD/LAB-International) to establish traceability and quality assurance in U.S. crime laboratories, a NIST/ATF joint project entitled National Ballistics Imaging Comparison (NBIC) was initialized in 2008. The NBIC project aims to establish a National Traceability and Quality System for ballistics identifications in crime laboratories within the National Integrated Ballistics Information Network (NIBIN) of the U.S. NIST Standard Reference Material (SRM) 2460 bullets and 2461 cartridge cases are used as reference standards. 19 ballistics examiners from 13 U.S. crime laboratories participated in this project. They each performed 24 periodic image acquisitions and correlations of the SRM bullets and cartridge cases over the course of a year, but one examiner only participated in Phase 1 tests of SRM cartridge case. The correlation scores were collected by NIST for statistical analyses, from which control charts and control limits were developed for the proposed Quality System and for promoting future assessments and accreditations for firearm evidence in U.S. forensic laboratories in accordance with the ISO 17025 Standard.     

The Impact of Gravity-Weighted Knowledge Spillovers on Productivity in Manufacturing

This paper tests for localized knowledge spillovers from out-of-state innovations in U.S. manufacturing from 1977 to 1997. The source of these spillovers is innovations categorized into six technologies based on U.S. patent classes and patent data. Using a gravity-weighting for out-of-state innovations, knowledge spillovers are found from mechanical technologies and drug and medical technologies for a broad group of manufacturing industries. Innovations from chemical-related technologies are found to generate spillovers for the Chemical and Allied Products Industry and for the Transportation Equipment Industry. Additionally, specialization of production at the two-digit Standard Industrial Classification of industry level is also found to increase state-level productivity in manufacturing.     

Statistical evaluation of truncated breath-alcohol test measurements

The reporting of breath-alcohol measurements truncated to two decimal places is a form of computational error. The magnitude of the error can range from 0.000 to 0.009 g/210 L. The truncation error will follow a uniform distribution. A total of 500 breath-alcohol test measurements were evaluated to determine the distribution of the third digit. There are 10 possible discrete values for the third digit. The frequency of each third digit was found to range from 44 for the lowest to 57 for the highest. The data closely approximated the uniform distribution. To conform exactly with the uniform distribution, there would have to be 50 of each decimal value. Given that the third digit approximates the uniform distribution, one cannot attach a greater probability to a particular third-digit value as opposed to another.     

Effect of hyperthermia on breath-alcohol analysis

Mild hyperthermia to the extent of a 2.5 degrees C increase above normal body temperature was produced by immersion of ethanol-intoxicated subjects in a warm water bath. Hyperthermia did not influence the blood-alcohol decay curve of the subjects. Hyperthermia did cause a significant distortion of the breath-alcohol decay curve, up to as much as a 23% increase above blood-alcohol concentration. The magnitude of this distortion effect was calculated to be a 8.62% increase in breath-alcohol concentration over blood-alcohol concentration for each degree C increase in core body temperature. The forensic relevance of these results is that further support is given to previous recommendations that temperature monitoring be included in procedures for breath-alcohol analysis. This leads to the recommendation that mouth temperature be measured before breath sampling to screen for abnormal body temperature and to allow for potential use of a "temperature correction factor." This modification to existing analytical procedures would optimize the reliability of breath-ethanol analysis for prediction of blood-ethanol concentration.     

Evaluation of breath-alcohol instruments. III. Controlled field trial with Alcolmeter pocket model

A breath-alcohol screening device, Alcolmeter pocket model, was evaluated in a controlled field trial with policeman operating the instruments. The results of tests made with subjects before they drank alcohol were always zero. The standard deviation (S.D.) of breath alcohol determinations increased with increase in the concentration of alcohol in the sample, being 0.036 mg/ml at a mean blood-ethanol concentration of 0.53 mg/ml. The S.D. varied among subjects tested (from 0.022 to 0.053 mg/ml) as well as among the instruments used (from 0.023 to 0.054 mg/ml). The breath test results were on average less than the actual blood-ethanol concentrations when a 2100: 1 blood/breath ratio was used to calibrate the Alcolmeter device. Blood ethanol (x) and Alcolmeter readings (y) were highly correlated (r = 0.95 +/- 0.018) and the regression equation was y = -0.017 + 0.95x. At a mean blood-ethanol concentration of 0.50 mg/ml, the Alcolmeter instrument will indicate 0.46 mg/ml on average. The standard error estimate was 0.085 mg/ml, being 17% of the mean Alcolmeter reading and this corresponds to 95% confidence limits of +/- 0.17 mg/ml. The results of this study show that Alcolmeter pocket-model is a useful device for breath-alcohol screening purposes at a blood-alcohol level of 0.50 mg/ml. A blood/breath ratio of 2300 should be used to calibrate the Alcolmeter device.     

Report on the 2003 revision of the U.S. Standard Certificate of Death.

The National Center for Health Statistics (NCHS) is responsible for publishing Standard Certificates of Birth and Death for the United States of America. The standard certificates are revised roughly every 10 years. The revision process is designed to ensure that the standard certificates meet, as nearly as possible, the use for which they are intended at all levels: individual, local, state, and federal. The authors report on the most recent revision of the U.S. Standard Certificate of Death, recording the process and the role of the National Association of Medical Examiners in the process. Changes recommended during revision include requesting known aliases of a decedent and rearrangement of the certificate to provide more room for those items requesting dates and for describing how the injury occurred. New items have been added asking for information regarding traffic fatalities, the role of tobacco use in causing death, and whether female decedents were pregnant. Once approved by the Department of Health and Human Services, the new standard certificate will be made available to the states. Each state will have 2 years to adapt the U.S. Standard Certificate of Death to its use and to implement new state death certificates on January 1, 2003.     

Evaluation of breath-alcohol instruments. IV. Roadside tests with Alcolmeter pocket model

This paper reports results from a field trial with a breath-alcohol screening device--Alcolmeter pocket model. Breath tests were made with drivers apprehended during routine controls (road-blocks), for traffic violations and those involved in traffic accidents. Of 908 roadside breath tests made with chemical reagent tubes, 343 showed zero alcohol (no colour change) and these results were confirmed by Alcolmeter. Alcohol was detected in 191 tests but the level was judged as being below the legal limit of 0.50 mg/ml. The Alcolmeter results, however, ranged from 0 to 1.22 mg/ml (mean 0.21 mg/ml) and 15 individuals (7.8%) were above the legal limit. There were 373 positive chemical tube breath screening tests whereas in 5 cases (1.3%) Alcolmeter indicated a blood-alcohol level below 0.50 mg/ml. Duplicate determinations with the Alcolmeter device were highly correlated r = 0.93 +/- 0.02 (+/- S.E.), P less than 0.001. The standard deviation of a single breath-alcohol analysis under field conditions was +/- 0.10 mg/ml which corresponds to a coefficient of variation of 10%. The time interval between positive roadside breath test and blood-sampling ranged from 5 to 220 min (median 62 min). The results were therefore adjusted by 0.15 mg/ml per hour to compensate for ethanol metabolised between the time of sampling blood and breath. The corrected blood and breath values were well correlated r = 0.84 +/- 0.03, P less than 0.001 but the predictive power of the regression relationship was poor. The regression equation was y = 0.27 +/- 0.65x and the standard error estimate was +/- 0.21 mg/ml at the mean concentration of ethanol of 1.0 mg/ml.     

Technological, economic, and political feasibility in OSHA's Air Contaminants Standard

In 1989, after almost two decades of substance-by-substance standard setting, the Occupational Safety and Health Administration (OSHA) promulgated its Air Contaminants Standard, imposing new exposure limits for 376 toxic substances encountered in U.S. industry. In marked contrast to earlier regulations, the Air Contaminants Standard has generated relatively little industry opposition. This paper analyzes the standard in the context of the twenty-year debate over the appropriate role for technological feasibility and economic compliance costs in occupational health policy. The political feasibility of the new standard is traced to OSHA's abandonment of "technology forcing" in favor of reliance on "off-the-shelf" technologies already in use in major firms. While important as an embodiment of OSHA's new "generic" approach to regulation, the Air Contaminants Standard cannot serve as a model for future occupational health policy, due to its reliance on informal, closed-door mechanisms for establishing regulatory priorities and permissible exposure limits.     

Reliability of breath-alcohol analysis in individuals with gastroesophageal reflux disease.

Gastroesophageal reflux disease (GERD) is widespread in the population among all age groups and in both sexes. The reliability of breath alcohol analysis in subjects suffering from GERD is unknown. We investigated the relationship between breath-alcohol concentration (BrAC) and blood-alcohol concentration (BAC) in 5 male and 5 female subjects all suffering from severe gastroesophageal reflux disease and scheduled for antireflux surgery. Each subject served in two experiments in random order about 1-2 weeks apart. Both times they drank the same dose of ethanol (approximately 0.3 g/kg) as either beer, white wine, or vodka mixed with orange juice before venous blood and end-expired breath samples were obtained at 5-10 min intervals for 4 h. An attempt was made to provoke gastroesophageal reflux in one of the drinking experiments by applying an abdominal compression belt. Blood-ethanol concentration was determined by headspace gas chromatography and breath-ethanol was measured with an electrochemical instrument (Alcolmeter SD-400) or a quantitative infrared analyzer (Data-Master). During the absorption of alcohol, which occurred during the first 90 min after the start of drinking, BrAC (mg/210 L) tended to be the same or higher than venous BAC (mg/dL). In the post-peak phase, the BAC always exceeded BrAC. Four of the 10 subjects definitely experienced gastric reflux during the study although this did not result in widely deviant BrAC readings compared with BAC when sampling occurred at 5-min intervals. We conclude that the risk of alcohol erupting from the stomach into the mouth owing to gastric reflux and falsely increasing the result of an evidential breath-alcohol test is highly improbable.     

Observations on the specificity of breath-alcohol analyzers used for clinical and medicolegal purposes

This paper deals with the application of three kinds of breath-alcohol analyzer for clinical and medicolegal purposes. The limited specificity for analyzing ethanol in expired breath has given misleading information with potential serious consequences. Three different methods of alcohol analysis are reported: semiconductor sensing (Alcotest 7310), electrochemical fuel cell (Alcolmeter SM-1), and infrared (IR) absorptiometry (IR Intoximeter 3000). Methanol could not be distinguished from ethanol with any of these breath-test instruments. When nonspecific techniques of ethanol analysis are used, the results must be considered with caution when interfering substances expelled in breath cannot be excluded.     

An application of probability theory to a group of breath-alcohol and blood-alcohol data

Many jurisdictions have "per se" driving-while-intoxicated (DWI) status expressed in terms of a blood-alcohol concentration (BAC) standard (in grams per 100 mL or the equivalent). Since breath-alcohol (BrAC) analysis is typically employed to determine BAC, there is often challenge to the use of an assumed 2100:1 conversion ratio. This concern may be relevant in light of considerable data that show a low percentage of cases in which BrAC greater than BAC, and this concern increases when the BrAC is used to predict BAC in the context of "per se" legislation. Probability theory provides a basis for estimating the likelihood of an individual having a BrAC greater than or equal to g/210 L with a corresponding BAC less than 0.10 g/100 mL. Actual field data from the state of Wisconsin (n = 404) were evaluated to determine the probability of this occurrence. The probability for this occurrence involves the multiplication law for independent events. The computed probability from the data was 0.018. The actual number of occurrences where BrAC greater than or equal to 0.10 g/210 L and BAC less than 0.10 g/100 mL was 5, resulting in a probability of 0.012. The concern of having BrAC greater than BAC at the critical "per se" level has a very low probability of occurrence, which thus supports the reasonableness of "per se" DWI legislation based upon a blood-alcohol standard determined by breath-alcohol analysis.     

RFLP band size standards: NIST standard reference material 2390

The procedural standard for DNA profiling developed by the U.S. advisory board on DNA quality assurance methods mandates annual confirmation of forensic DNA measurement systems against an appropriate reference material supplied by or traceable to the National Institute of Standards and Technology (NIST). NIST Standard Reference Material (SRM) 2390 is a suitable and appropriate standard for HaeIII restriction enzyme-based restriction fragment length polymorphism (RFLP) profiling systems. Originally issued in 1992, an among-laboratory SRM 2390 recertification study was initiated in 1997. Using data provided by the 20 state, local, or commercial forensic laboratory participants, quantitative band sizes values (expected mean values and associated bivariate tolerance intervals) are established for two different-source DNAs (female cell line K562 and healthy male "TAW") for genetic loci D1S7, D2S44, D4S139, D5S110, D1OS28, and D17S79. Methods for validating an RFLP measurement system, validating a control material or other secondary standard, and for tracing a particular set of RFLP measurements to NIST SRM 2390 are described in detail.     

The single most polymorphic STR Locus: SE33 performance in U.S. populations

The STR locus SE33 (ACTBP2) located on chromosome 6 (6q14) is arguably the most polymorphic marker examined thus far by the forensic community with a heterozygosity of >0.95 in some populations. Three different primer sets were utilized in this study in order to assess the possibilities of primer binding site mutations. Population variation was measured in 460 U.S. Caucasian, 445 African American, 336 Hispanic, and 202 Asian samples along with mutation rates from almost 400 father–son pairs. In addition, the 10 genomic DNA components in NIST Standard Reference Material SRM 2391b were sequenced and found to exhibit a variety of additional base changes, insertions, and deletions outside of the SE33 repeat region.     

The Effectiveness of Trace DNA Profiling—A Comparison Between a U.S. and a U.K. Law Enforcement Jurisdiction

Recovery, profiling, and speculative searching of trace DNA (not attributable to a body fluid/cell type) over a twelve‐month period in a U.S. Crime Laboratory and U.K. police force are compared. Results show greater numbers of U.S. firearm‐related items submitted for analysis compared with the U.K., where greatest numbers were submitted from burglary or vehicle offenses. U.S. multiple recovery techniques (double swabbing) occurred mainly during laboratory examination, whereas the majority of U.K. multiple recovery techniques occurred at the scene. No statistical difference was observed for useful profiles from single or multiple recovery. Database loading of interpretable profiles was most successful for U.K. items related to burglary or vehicle offenses. Database associations (matches) represented 7.0% of all U.S. items and 13.1% of all U.K. items. The U.K. strategy for burglary and vehicle examination demonstrated that careful selection of both items and sampling techniques is crucial to obtaining the observed results.     

Driving under the influence of chlormethiazole

This article describes a case of driving under the influence of the sedative-hypnotic-anticonvulsant drug chlormethiazole. The suspect, who was a physician, was driving dangerously on a busy highway and caused a traffic collision. When apprehended by the police, the man had bloodshot and glazed eyes and pupil size was enlarged. He could not answer the questions properly and his gait was unsteady. A roadside breath-alcohol screening test was positive but an evidential breath-alcohol test conducted about one hour later was below the legal limit for driving of 0.10 mg/L (10 microg/100 mL or 0.021 g/210 L). Because of the special circumstances of the traffic crash and the man's appearance and behaviour, the police suspected that drugs other than alcohol were involved and obtained a venous blood sample for toxicological analysis. The blood contained 0.23 mg/g alcohol, which is above the legal limit for driving in Sweden 0.20 mg/g (20 mg/100 mL or 0.020 g/100 mL), and codeine was also present at a therapeutic concentration of 0.02 mg/L. The conflict between the clinical signs of impairment and the toxicology report prompted a reanalysis of the blood sample with major focus on sedative-hypnotic drugs. Analysis by capillary GC-NPD identified chlormethiazole at a concentration of 5mg/L, the highest so far encountered in traffic cases in Sweden. In 13 other impaired driving cases over 10 years the mean (median) and range of concentrations of chlormethiazole were 1.6 mg/L (1.6 mg/L) and 0.3-3.3 mg/L. This case report underscores the need to consider clinical observations and the person's behaviour in relation to the toxicology report when interpreting and testifying in drug-impaired driving cases.     

Administrative License Revocation in New Mexico: An Evaluation

Swiftness of punishment for drivers impaired by alcohol is likely to be increased objectively by administrative license revocation laws. These laws provide that a driver who fails or refuses a breath-alcohol test has his license confiscated on the spot by police, with formal loss of driving privileges following shortly thereafter. This study of New Mexico law looks for evidence of a deterrent impact of administrative license revocation. Interrupted time-series analysis finds a permanent drop in the proportion of driver and pedestrian fatalities involving the presence of alcohol precisely at the time that the law went into effect. However, lack of publicity for the law and the existence of a complex procedure, unpopular with many police, appear to have diminished the law's effectiveness.     

Why are some foreign-born workers more entrepreneurial than others?

Foreign-born workers have made significant and substantial contributions to economic productivity and new firm creation in the United States. This paper identifies predictors of entrepreneurial participation among foreign-born workers, combining nationally representative survey datasets covering the U.S. resident, college-educated workforce with country-of-origin macro statistics from the Global Entrepreneurship Monitor. Immigrants who come to the U.S. after earning university degrees abroad are more likely to own businesses than other college-educated, U.S. resident workers. However, much of their higher rate of business ownership can be attributed to differences in demographic characteristics, such as years of postgraduate work experience and marital status. By contrast, science and engineering-based business ownership is most common among immigrants who came to the U.S. to pursue higher education. Furthermore, after controlling for differences in human capital, U.S.-trained adult immigrants have higher propensity to own businesses than other foreign-born workers and native U.S. citizens, overall. U.S.-trained immigrants’ higher probability of business ownership is not explained by differences in human capital or other demographic characteristics, but does seem partly attributable to differences across foreign-born workers’ countries-of-origin. Specifically, adult immigrants and foreign temporary residents from countries that offer entrepreneurs lower levels of cultural support are more likely to start and own U.S. businesses.     

Information flow from Japan to U.S. researchers in applied and basic energy research fields

A recent study conducted by Pacific Northwest Laboratory (PNL) evaluated technical information transfer from Japan to the United States. This evaluation was part of a larger assessment of international monitoring of energy technology development conducted for the U.S. Department of Energy. For this study, U.S. researchers in each of ten selected technical fields were identified and interviewed to obtain their perceptions of information transfer from Japan. Results from these interviews indicated that, although there are major differences among the technical fields, U.S. researchers generally consider information transfer from Japan to the U.S. to be inadequate. Researchers particularly noted the difficulties they have attending conferences in Japan or visiting Japanese research facilities. In contrast, Japanese researchers attend all major conferences and frequently visit laboratories in the U.S. Researchers recommended several steps to improve technology transfer from Japan, including improving the screening and translation of technical material published in Japan, promoting binational seminars and workshops, and encouraging laboratory visits and exchanges of research personnel.     

A Comparison of US and UK Asbestos Liability

This article compares the impact of asbestos liabilities in the U.S. with that in the U.K. The maximum exposure to asbestos in the U.S. occurred during the time period from the 1930s to the 1960s. In the U.K., the peak asbestos exposure likely occurred during the 1960s and the 1970s. Asbestos-related deaths are projected to have peaked before 1997 in the U.S. Asbestos-related deaths in the U.K. are projected to peak sometime before 2020—some 20 years after those in the U.S. In the U.S., asbestos-related claims are believed to have peaked around 2002. Given the anticipated peak in asbestos-related disease deaths in the U.K., the peak in asbestos-related claims in the U.K. will likely occur sometime after 2020. There are differences in judicial systems and victim compensation schemes (private and public) between the U.S. andthe U.K. However, trends in recent U.K. court decisions and regulatory activities (as well as increases in victim awareness, litigation, on-going discovery, victim support groups, and claim compensation) suggest that the U.K.'s current asbestos liability situation may be analogous to what the U.S. experienced in the mid-1980s, and that the impact on the U.K. courts and economy may be far from over.