The percentage of positive tests for methamphetamine among U.S. job applicants and workers in the general U.S. workforce dropped more than 22 percent between 2006 and 2007. These findings, from the Quest Diagnostics Drug Testing Index®, reflect the reversal of an upward trend in use of the drug by more than 73 percent from 2002 to 2004. These data were released today by Quest Diagnostics Incorporated , the nation's leading provider of employment-related drug testing services. The report also shows that positive tests for cocaine in the general U.S. workforce were down 19 percent between 2006 and 2007 and that overall drug use, among workers subject to drug testing, remains at an all-time low.

Methamphetamine, the most commonly abused type of amphetamine, increased in production and trafficking during the 1990's to become the most prevalent illegally manufactured synthetic drug in the United States. Analysis of the Quest Diagnostics Drug Testing Index, released semi-annually, suggests that efforts to reduce illicit, clandestine production of methamphetamine may be having an impact on workplace positive tests for the drug.

"The fact that America's workers are using cocaine and methamphetamine at some of the lowest levels in years is further evidence of the tremendous success that law enforcement is having at impacting the nation's illicit drug supply," said DEA Acting Administrator Michele M. Leonhart. "DEA will continue its relentless assault on the drug supply to help keep these dangerous drugs out of our neighborhoods."

While the 2007 Quest Diagnostics Drug Testing Index shows that positive methamphetamine tests have decreased, it also indicates that the use of amphetamine in the general workforce has increased slightly, by about five percent. Testing for methamphetamine and amphetamine was conducted among employees and applicants in the U.S. workforce tested for the class of drugs called amphetamines.

"Although some may conclude that there is a reduced availability for methamphetamine, the fact that our data show an increase in amphetamines suggests that some workers might be replacing one stimulant drug for another in the larger drug class of amphetamines," said Barry Sample, Ph.D., Director of Science and Technology for Quest Diagnostics' Employer Solutions division.

Methamphetamine and amphetamine are both types of stimulants, which typically are used by individuals to increase alertness and relieve fatigue. Stimulants are also used for euphoric effects or to counteract the "down" feeling of tranquilizers or alcohol. Possible side effects of stimulants include increased heart and respiratory rates, elevated blood pressure, dilated pupils and decreased appetite. High doses may cause rapid or irregular heartbeat, loss of coordination or collapse. Indications of possible misuse may include excessive activity, talkativeness, irritability, argumentativeness or nervousness.

Cocaine Use Continues to Decline

The Quest Diagnostics Drug Testing Index shows that the percentage of positive tests for cocaine was down 19 percent among the U.S. general workforce since the first half of 2007 - the largest single-year drop since 1997. Positive tests for cocaine among the general workforce declined to 0.58 percent in 2007 from 0.72 percent in 2006.

Overall Drug Use Remains at All-Time Low

Additionally, drug use by employees remains at its lowest level since Quest Diagnostics began publishing the Drug Testing Index in 1988. Among the combined U.S. workforce, only 3.8 percent of the tests had positive results -- the same level reported in 2006 -- compared to a high of 13.6 percent in 1988. Further, among safety-sensitive federal workers only, the Drug Testing Index showed that drug use was at an all-time low of 1.8 percent of the tested work force.

The 2007 Drug Testing Index is a summary of results from 8.4 million workplace drug tests performed by Quest Diagnostics between January and December 2007. Results are based on tests that Quest Diagnostics performs for employers that conduct pre-employment, random or for-cause drug testing. For more information, see additional results online at www.questdiagnostics.com.

About the Drug Testing Index

The Drug Testing Index is published as a public service for government, media and industry and has been considered a benchmark for national trends since its inception in 1988. It examines positivity rates - the proportion of positive results for each drug to all such drug tests performed - among three major testing populations: federally mandated, safety-sensitive workers; the general workforce; and the combined U.S. workforce. Federally mandated, safety-sensitive workers include pilots, bus and truck drivers, and workers in nuclear power plants, for whom routine drug testing is mandated by the U.S. Department of Transportation and the Nuclear Regulatory Commission.

About Quest Diagnostics

Quest Diagnostics is the leading provider of diagnostic testing, information and services that patients and doctors need to make better healthcare decisions. The company offers the broadest access to diagnostic testing services through its national network of laboratories and patient service centers, and provides interpretive consultation through its extensive medical and scientific staff. Quest Diagnostics is a pioneer in developing innovative new diagnostic tests and advanced healthcare information technology solutions that help improve patient care. Additional company information is available at: www.questdiagnostics.com.

The statements in this press release which are not historical facts or information may be forward-looking statements. These forward-looking statements involve risks and uncertainties that could cause actual results and outcomes to be materially different. Certain of these risks and uncertainties may include, but are not limited to, competitive environment, changes in government regulations, changing relationships with customers, payers, suppliers and strategic partners and other factors described in the Quest Diagnostics Incorporated 2007 Form 10-K and subsequent SEC filings.

The Drug Testing Index© 2008 Quest Diagnostics Incorporated. All rights reserved.

  Positive Prevalence Rates for Amphetamine and Methamphetamine - Percentage
  of All Tests for "Amphetamines"

                             2007      2006      2005      2004      2003
  Amphetamine                0.40%     0.38%     0.44%     0.45%     0.41%
  Methamphetamine            0.14%     0.18%     0.28%     0.33%     0.32%

  Percent Difference -
   Amphetamine               5.3%     -13.6%     -2.2%      9.8%
  Percent Difference -
   Methamphetamine         -22.2%     -35.7%    -15.2%      3.1%


  Positivity Rates for Cocaine

                             2007      2006      2005      2004      2003
  Cocaine                    0.58%     0.72%     0.70%     0.72%     0.74%

  Percent Difference -
   Cocaine                  -19.4%      2.9%     -2.8%     -2.7%

SOURCE: Quest Diagnostics Incorporated

CONTACT: Laure Park, Investors, +1-973-520-2900, or Nancy Fitzsimmons,
Media, +1-973-520-2800, both of Quest Diagnostics Incorporated

Web site: http://www.questdiagnostics.com/