See the above link for United States Supreme Court Justices quoting my work regarding neurotoxic causes of crime.

Some Career Highlights and Forensic Achievements of Dr. Raymond Singer


1978: Awarded the Doctor of Philosophy degree from Washington State University, Department of Psychology.

1979: Awarded the National Institute of Health Post-Doctoral Fellow in Biological Psychiatry, Millhauser Laboratory, New York University Medical Center, New York City.


1980: Awarded the National Institute of Health Post-Doctoral Fellow in Environmental Epidemiology, Mount Sinai School of Medicine, New York City, under the direction of Dr. Irving J. Selikoff, one of the top applied toxicologists in the world, who brought the dangers of asbestos to the world's attention.

1982: Published research demonstrating the harmful effects of dioxin on the human nervous system (one of the first on this topic)

Singer, R., Moses, M., Valciukas, J., Lilis, R., & Selikoff, I. J. (1982). Nerve conduction velocity studies of workers employed in the manufacture of phenoxy herbicides. Environmental Research, 29, 297-311.

1983: Began independent practice as a neuropsychologist and a neurotoxicologist.

1984: Served as one of approximately 6 expert medical witnesses in the Agent Orange Vietnam Veterans' Litigation. This class action suit was settled out-of-court in 1984 for $180 million dollars, reportedly the largest settlement of its kind at that time (equivalent to $438 million in 2019 dollars). This case expanded the concept that neurotoxicity can cause permanent and debilitating injuries, compensable by courts, and exposed the role of dioxin in causing neurotoxicity.

Read More Here

Fast forward to 2018. Although Dr. Singer's opinion that dioxin could damage the peripheral and central nervous system was disputed by the defense "toxicology experts" in the Agent Orange litigation, his opinions have stood the test of time. Thirty years after testifying regarding the neurotoxicity of dioxin, a year 2018 study of dioxin-exposed workers confirmed Dr. Singer's opinion and the veteran's pleas, showing both peripheral and central nervous system dysfunction in dioxin workers, unrelieved years after exposure.

The last eight survivors of 80 workers accidentally exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) during production of herbicides based on trichlorophenoxyacetic acid in 1965-1967 in a chemical factory were followed. All were men, mean age 72.4 ± 1.3 years. Their current median TCDD blood level was 112 (46-390) pg/g lipids. Neurological examination revealed central nervous system impairment in all individuals and signs of polyneuropathy in 87.5%, which was confirmed by a nerve conduction study (NCS) in 75%. A Lanthony test demonstrated acquired dyschromatopsia in 87.5% of the patients, with deterioration of mean colour confusion index (CCI) from 1.52 ± 0.39 in 2010 to 1.73 ± 0.41 in 2016. Single-photon emission computer tomography (SPECT) of the brain showed focal reduction of perfusion in various brain locations in all patients and worsening in six patients. Visual-evoked potentials (VEP) was abnormal in 62.6% of individuals. Most patients complained of psychological problems. The neuropsychological test battery showed most positive impairments in the Trail Making Test evaluating processing speed (average level in the range of mild neurocognitive impairment), which correlated with mean CCI (p < 0.05).
 2018 Feb;122(2):271-277. doi: 10.1111/bcpt.12899. Epub 2017 Sep 27. Neurological and Neurophysiological Findings in Workers with Chronic 2,3,7,8-Tetrachlorodibenzo-p-Dioxin Intoxication 50 Years After Exposure.

1987: With blind funding from Archer Daniels Midland and the National Renewable Fuels Association, Dr. Singer researched and developed a report regarding the advisability and neurotoxicity of certain gasoline additives, entitled The Toxicity of Gasoline Additives, circulated among U.S. Congress and staff. In this report, Dr. Singer alerted Congress that methyl tetrabutyl ether (MTBE), used as a gasoline additive, would have serious toxic consequences.

Unfortunately and against my recommendations, the US Congress authorized MTBE as a fuel additive, which incurred very harmful effects.

The following is from

At its zenith, MTBE commanded center stage in both the oil and chemical industries as companies raced to build new plants to meet the anticipated surge in demand in the US gasoline market - the world's biggest - after the blendstock was touted as the cure-all to combat rising pollution.

By 2002, global demand for MTBE was approaching 22m tonnes/year, with the US responsible for nearly 60% of consumption. Plants had been built worldwide to service projected demand.

Yet by the late 1990s, MTBE's demise in the US as a fuel oxygenate was on the cards. It started with drivers in Alaska feeling dizzy when filling their tanks in the arctic winter. Reports of the chemical seeping into the groundwater of health-conscious Americans raised alarm. Calls for its use to be stopped in the US grew less than 10 years after its glowing debut.


Two studies, commissioned by the American Water Works Association (AWWA) and the Association of Metropolitan Water Agencies (AMWA), examined the cost to remove methyl tertiary butyl ether (MTBE) contamination from public drinking water systems across the United States. These studies update estimates from 2001 that then cited MTBE cleanup costs at approximately $29 billion. The new studies indicate that the cleanup costs are likely to be in the range of $25-$33.2 billion and could be as high as $85 billion or more.

"The U.S. Supreme Court on Monday rejected Exxon Mobil Corp’s appeal of a $236 million judgment against the oil company in a case brought by the state of New Hampshire over groundwater contamination linked to a gasoline additive.

The justices left in place the New Hampshire Supreme Court’s 2015 ruling upholding the judgment by a jury that in 2013 spurned Exxon’s claims that the contamination linked to its fuel additive was not its fault but rather the fault of the local gas stations and storage facilities that spilled it... The additive at the center of the case is called methyl tertiary butyl ether, or MTBE. It is an oxygen-containing substance that was added to gasoline to promote more complete combustion and reduce air pollution."

The MTBE litigation continues "Maryland sues petroleum companies over groundwater contamination... The lawsuit, filed Wednesday in Baltimore City Circuit Court by Maryland Attorney General Brian E. Frosh’s office, alleges that ExxonMobil, Chevron, and dozens other companies knew a fuel additive called methyl tertiary butyl ether, or MTBE, would contaminate groundwater and tried to obstruct research about its harmful effects.

1987: Developed the Neurotoxicity Screening Survey, an instrument to determine the consistency of symptoms in patients diagnosed with neurotoxicity.


1990: Published the Neurotoxicity Guidebook. The publisher was Van Nostrand Reinhold, a major industrial hygiene/toxicology publisher at that time. This text, still in print, is one of the few single-author texts on the subject.

1990: Elected as a Fellow, American Psychological Association in recognition of "outstanding, substantial and unusual contribution to psychology". Approximately 2% of American psychologists had been elected to this status when awarded in 1990.

1991: Consultant in neuropsychology and neurotoxicology, United States Department of Justice, Environmental Crimes Section, and Federal Bureau of Investigation. On their behalf, Dr. Singer conducted an investigation of a hazardous solvent waste neurotoxicity case.

1992: Served as an expert witness in landmark litigation where the Ohio Supreme Court unanimously accepted the testimony of Dr. Raymond Singer, stating "a witness who is not a physician, but who qualifies as an expert under [state evidence rules] may give evidence that would be relevant to diagnosis of a medical condition" - in this case, a multiple sclerosis type condition from gasoline exposure. The court also reviewed my qualifications and stated: "Dr. Singer has an extensive and impressive vita dealing with psychology, biological effects on the central nervous system, and neurotoxicology. He has been a fellow at the National Institute of Health and at the Mount Sinai School of Medicine, has won the NIH National Research Service Award, and has a long list of publications dealing with neurotoxicity and its effects. He is qualified by "knowledge, skill, experience, training, or education" to testify on the subject of toxicity of gasoline on the human nervous system."

Shilling v. Mobile Analytical Servs., Inc., 602 N.E.2d 1154 (Ohio 1992). Cited in published rulings at least 9 times as of 2021.

1993: Board-Certified Diplomate in Neuropsychology, American Board of Professional Neuropsychology

1997: Served as an expert in Birklid et al. v. Boeing, Washington state, wherein the Court permitted claimants the right to directly sue employers for toxic injuries in certain worker's compensation claims. Birklid v. Boeing, a 1995 en banc (9-0) decision of the state Supreme Court, changed Washington State law regarding employer liability for “deliberate” injury by allowing, for the first time in 83 years, a disputed claim of deliberate injury to proceed against the state’s largest employer (Read More Here). This was a decade-long battle culminating in the Washington Supreme Court successfully confirming Washington law in favor of protecting injured workers deliberately exposed to toxic chemicals and other injurious workplace conditions. Read More Here.

Cited in published opinions at least 137 times as of 2021

1997: In Scaffidi v. Thompson-Hayward Chemical Inc., DC ELa, No. 94-3860, 8/12/97, the defense tried to limit the ability of plaintiffs to have neuropsychologists give medical causation, however, the court allowed a claim against the facility's former owner to proceed, finding the medical causation proof of an organic brain dysfunction offered by a neuropsychologist experienced in neurotoxicology sufficient to allow the claim to proceed (Volume 12 Number 16, Wednesday, September 17, 1997, ISSN 1522-5240, TOXIC TORTS: OCCUPATIONAL EXPOSURE)

1994-1999: Served as president and other elected positions for the Roundtable of Toxicology Consultants (an organization of independent, consulting toxicologists, composed of consultant members of the Society of Toxicology - the premier organization of toxicologists in the world).

1999: Upon the invitation of the German Federal Government, SPD Bundestagfraktion, Dr. Singer addressed The Great Assembly Hall of Parliament (Deutscher Bundestag), Wasserwerk, Bonn, Germany.


2001: Served as an expert witness in a landmark United States Appeals Court decision, enabling plaintiffs to seek compensation for injuries even if the toxicology/medical literature is incomplete.

The case involved motor dysfunction, tremor and other neuropsychological dysfunctions in a plaintiff exposed to a novel solvent, of which the toxicological database is incomplete.

The Federal Appeals Court ruled as follows:

The first several victims of a new toxic tort should not be barred from suit simply because medical literature, which will eventually support causal connection, has not yet been completed.

Plaintiffs need not produce mathematically precise tables equating levels of exposure with levels of harm, but need merely offer evidence from which jurors can reasonably conclude that exposure probably caused injuries.

There is no requirement that plaintiff's expert must always cite published studies on general causation, nor that pertinent epidemiological studies supporting plaintiff's position exist.

Even if trial judge believes there are better grounds for some alternative conclusion, and that there are some flaws in expert's methods, expert's opinion should be admitted if there exist good grounds to support it. Only question is whether testimony is sufficiently reliable and relevant to assist jury.

The manufacturer attempted to exclude my testimony under Daubert rules, but my testimony and the original verdict were upheld by the Court. The plaintiff was awarded $2.1 million - more than doubling the prior-to-trial settlement offer by the plaintiffs - and a precedent-setting verdict in that jurisdiction. (Bonner v. ISP Techs., Inc., 259 F.3d 924 (8th Cir. 2001)).

As of 2021, this case was cited in at least 384 subsequently published decisions

This case was cited by The American Bar Association's Scientific Evidence Review: Admissibility of Use of Expert Evidence in the Courtroom. Monograph Number 6. American Bar Association: Section of Science and Technology Law (June 3, 2003).

 Read More Here

2001: Behavioral dyscontrol is a well-known outcome of brain injuries, such as may occur after brain trauma. However, the brain can also be injured by toxic chemicals, even without any outward appearance of an injury. This injury can decrease the person's capacity to control his emotions, and in extreme cases, can result in violent crime. Even if a person is found guilty of a crime, the jury is instructed to consider mitigating circumstances when deciding the penalty. Dr. Singer served as an expert witness concerning a defendant with extensive exposure to neurotoxic substances who committed multiple murders in one night (State of Missouri versus DeLong). DeLong faced the death penalty. Dr. Singer testified that toxic chemical poisoning altered DeLong's brain function, damaging his ability to think, plan and control his impulses. After an extensive trial, the defendant was spared the death penalty due to mitigating circumstances including neurotoxicity. 

a. This is the first case to my knowledge wherein neurotoxicity was a factor in mitigating the death penalty. Note that the issue was also reviewed by justices of the US Supreme Court in 2016 who relied upon my work - see below.

2004: Consultations with United States House of Representatives Henry Waxman, who was chair of the committee (United States House Committee on Energy and Commerce) that has oversight over the United States Food and Drug Administration (FDA). The FDA was seeking legislation to allow them to severely restrict the sale of herbal supplements, on the grounds that herbal supplement manufacturers were making unscientific health claims, and that consumers were being injured from taking herbal supplements.

Congressman Waxman consulted with me and my consultants in herbal medicine, and I informed Congressman Waxman that generally speaking, herbal medicine as marketed in the United States was generally safe and at times effective. Congress decided to continue to allow the sale of herbal supplements without requiring FDA approval. In a compromise with the FDA, herbal supplement manufacturers label the products with the following language

"This statement has not been evaluated by the FDA. This product is not intended to diagnose, treat, cure, or prevent any disease" - because according to the FDA, only a drug can legally make such a claim

In contrast to the FDA, consumers do believe that herbal products can treat or prevent disease, but this legal language was a necessary compromise for the continued sale of herbal products. As of 2015, the majority of U.S. adults—68 percent—take dietary supplements and consumer confidence remains high, with 84 percent of U.S. adults expressing overall confidence in the safety, quality, and effectiveness of dietary supplements.

This compromise permitted the growth of the US herbal supplement market to a forecasted $87 billion in 2022.

2004: Elected as a Fellow of the National Academy of Neuropsychology for "significant contributions to the Science and Profession of Neuropsychology", awarded to approximately only 213 neuropsychologists in the world at that time.

2004: Diplomate in Neuropsychology with Added Qualification in Forensic Neuropsychology, American Board of Professional Neuropsychology (12 such certifications awarded worldwide at that time).

2008: In a case that was on appeal with the US Veteran's administration with an incorrect diagnosis including somatoform disorder for many years,  Dr. Singer was able to demonstrate that a long-time disability was actually service-connected to a traumatic brain injury and subsequent electroconvulsive treatment.

In a US Veterans Administration appeals decision, Citation Nr: 0800354 Decision Date: 01/04/08,  Archive Date: 01/22/08  DOCKET NO.  05-34 988, I was able to demonstrate that a claimant had a brain injury from a traumatic brain injury and subsequent electroconvulsive treatment that rendered him disabled.  The veteran previously had been variously diagnosed with atypical somatoform disorder or schizophrenia. The veteran's claims of entitlement to service connection for a psychiatric disorder and residuals of a head injury were last denied in a September 1994 Board decision. That was 14 years prior to my work in the case, which resulted in a decision that the veteran was indeed disabled from his armed service.

From the decision: “Also of record is a neuropsychological assessment of Dr. Singer dated in August 2005.  This assessment notes the veteran's history of in-service head injury and subsequent discharge due to apparent schizophrenia.  After thorough evaluation, Dr. Singer concluded that it was unlikely that the veteran had schizophrenia after his discharge, although he did believe that the veteran had some brain dysfunction.  He further stated that the veteran did not then currently have schizophrenia and related schizophrenic-like conditions to traumatic brain injury.  Ultimately, Dr. Singer diagnosed organic brain dysfunction, affecting cognition, memory, and other brain functions, from a traumatic brain injury and electroconvulsive treatment...

Service connection is granted for disability resulting from disease or injury incurred or aggravated in active military service...Entitlement to service connection for residuals of a head injury is granted."


2009: Dr. Singer served as an expert witness in the State of Washington versus Zamora. Mr. Zamora faced the death penalty for a rampage of multiple murders, including a police officer and random motorists. Dr. Singer examined the defendant, studied the case extensively, then wrote a report and expressed his opinion that neurotoxicity from substances including mold mycotoxins had altered Zamora's brain function and damaged his ability to think, plan and control his impulses. The case settled without a trial, and the defendant was spared the death penalty.

Washington state agreed to pay $9 million to settle claims that this fatal shooting rampage could have been prevented (see here). These tragedies could be prevented if mental health professionals and other medical providers were more aware of the mental health consequences of neurotoxicity. What will it take to bring neurotoxicity to its proper level of awareness among our political leaders?

2009: Appellate decision: Served as an expert witness in a neurotoxicity case at the appellate level, wherein the appeals court judge accepted my opinion, overturned the lower court, and concluded that the claimant's injuries included chemical sensitivity, as well as toxic encephalopathy. In Washington State Board of Industrial Appeals Re: Steven Vaughn. Before the Board of Industrial Insurance Appeals, State of Washington in Re: Steven R. Vaughn Docket No. 10 12284 Claim No. Y-965493 

2009: Appellate decision: Served as an expert witness in a British Columbia Worker's Compensation Appeals Tribunal (Re: Paul Whitehead). The Appeals Tribunal in an 83-page decision accepted my opinion that neurotoxicity from mercury significantly injured a worker and that the worker was eligible for compensation.

2009: Daubert-type decision: On May 5, 2009, the court in Nicole Alexander et al. vs. Bozeman Motors, Inc., Montana 19th Judicial District Court, Gallatin, County, Cause No. DV-05-699, ruled that my testimony was based on "time-tested use of scientific methodology in the neurotoxicity field", and that the field of neurotoxicity in which I engage is reliable.


2010: Served as an expert witness in a State of Washington Industrial Insurance Appeals Court, wherein the judge reversed the lower court ruling, characterized me as highly qualified, and accepted my opinion that the worker was injured from her work at the Hanford Nuclear Reservation (Re: Diana Gegg).

This decision was later affirmed by a higher court, who stated: "We strongly agree with our industrial appeals judge's decision to allow this claim... Based on the evidence in our record, we have concluded that all of the five diagnoses made by Raymond M. Singer, Ph.D., are correct and we have ordered the Department to allow the claim for these conditions". Read More Here

2010: Authored an updated chapter on Forensic Neurotoxicology - Singer, R. (2010): Forensic neurotoxicology. In the Handbook of Forensic Neuropsychology, Second Edition. New York: Springer.

2011: Authored one of the first published works identifying neurotoxicity as a specific syndrome - The Neurotoxicity Syndrome - in Singer, R. (2011). Neurotoxicity in Neuropsychology. In Schoenberg, MR & Scott, JG. The Little Black Book of Neuropsychology: a Syndrome Based Approach. New York: Springer.

2013: Served as an expert witness in a California case of a bystander injured by a commercial product being applied by other workers. The product contained toluene diisocyanate (TDI). This substance is known to be a respiratory toxicant, but its neurotoxic effects were less well known.

After days of deposition cross-examination, wherein I explained the neurotoxicity of toluene diisocyanate, I was informed that the manufacturer altered the instructions on the product so that the product can be more safely applied. This was a gratifying and immediate effect of my testimony, with the implementation of product application guidelines that better protect workers - and bystanders  - from avoidable hazards when applying this product.

After this grueling and very thorough deposition,  the defendants settled the litigation with a generous offer that provided the plaintiff with lifetime income and paid all of his medical bills.

2015: The Veteran's Administration now recognizes that Agent Orange can cause peripheral neuropathy in veterans. However, this condition was known to be caused by Agent Orange at least since 1982. My testimony in the Agent Orange Vietnam Veteran's case in 1983 utilized research I had conducted and published in 1982 which showed peripheral neurotoxicity of Agent Orange (Singer, R., Moses, M., Valciukas, J., Lilis, R., & Selikoff, I. J. (1982). Nerve conduction velocity studies of workers employed in the manufacture of phenoxy herbicides. Environmental Research, 29, 297-311). Sometimes it takes quite a bit of time for neurotoxicity to be recognized by administrative authorities.

2015: Served as an expert witness in a case regarding the neurotoxic effect of mold in a child, resulting in a condition like mental retardation (severe developmental delays and likely permanent brain damage). As is typical in most litigation, the defense tried to have my testimony excluded, but the judge ordered my testimony to proceed.  The case settled on the basis of my reports, consultations, without the need for depositions or trial. The defendants generously gave enough to provide the plaintiff with a lifetime income.

2016: Neurotoxic injuries can settle in the range of $1.5 million, usually requiring a seasoned lawyer who is committed to justice. I have served as an expert witness in such cases.

2017: For those who are new to toxic chemical litigation, you may not know that the right of a plaintiff to present expert witnesses to a jury can be prevented. Defendants in toxic chemical litigation will routinely attempt to have expert testimony excluded so that a jury will not hear evidence that could be beneficial to the plaintiff. This tactic was attempted in 2017 in an Ohio state case, Crist v Columbia Gas et al.. However, this attack failed. The judge wrote: "Consistent with the holding in Shilling, this Court finds that Dr. Singer’s testimony in this case meets the test of Evid.R. 702."

Federal Rules of Evidence, Evid. R. Rule 702. Testimony by Expert Witnesses

A witness who is qualified as an expert by knowledge, skill, experience, training, or education may testify in the form of an opinion or otherwise if:
(a) the expert’s scientific, technical, or other specialized knowledge will help the trier of fact to understand the evidence or to determine a fact in issue;
(b) the testimony is based on sufficient facts or data;
(c) the testimony is the product of reliable principles and methods; and
(d) the expert has reliably applied the principles and methods to the facts of the case

2018: Served as an expert neuropsychologist/neurotoxicologist regarding a Camp LeJeune veteran. In part on the basis of my neuropsychological/ neurotoxicological assessment, the veteran was awarded 100% disability compensation for a relatively late-onset neurocognitive disorder resulting from exposure to water-borne solvents many years ago.

2018: Served as an expert neuropsychologist/neurotoxicologist regarding a neuropsychological injury from a psychiatric drug. In part on the basis of my neuropsychological/neurotoxicological assessment, the claimant was awarded 100% (time-limited) disability compensation.

2018: Appellate decision: Served as an expert witness in a difficult appeals case presented to the British Columbia Workers’ Compensation Appeal Tribunal (WCAT). (Decision of the Workers’ Compensation Appeal Tribunal, WCAT Decision Date: August 28, 2018, WCAT Decision Number: A1701400).

The case was originally tried in 2015. Compensation was denied three times for central nervous system dysfunction from solvent exposure in the claimant.

In 2018, Dr. Singer examined the claimant and reported his finding to the Court. He addressed the issues: does the claimant suffer central nervous system dysfunction from solvent exposures, as well as multiple chemical sensitivity (MCS).

In an August 28, 2018 decision, the Appeals judge wrote: 

"I am satisfied, for the reasons given, that resolution of this issue is most appropriately based on Dr. Singer’s interpretation of Dr. G’s neuropsychological testing results. With the benefit of this new evidence, I find that the worker has likely sustained permanent cognitive impairment from his exposure to organic solvents, and this impairment is consistent with his WHO Type II CSE diagnosis."

"Dr. Singer concluded that in terms of a forensic opinion, within reasonable scientific, neuropsychological, neurotoxicological, and professional certainty, the worker was suffering from multiple chemical sensitivity (MCS), which was an “effect” of his prior occupational exposures that had resulted in neurotoxicity...  I rely on the opinions of Drs. H and Singer to find it likely that the worker’s prior over-exposure to organic solvents and other toxic chemicals is of causative significance to his MCS." 

2019: I was informed that United States Supreme Court Justices Sotomayor and Ginsburg relied upon my work in neurotoxic causes of mental illness and crime in their opinion regarding a case in which I had provided expert services ( ). Their opinion was cited at least 4 times as of 2019, including two US Federal Court of Appeals decisions.

2019: EPA Bans Consumer Sales of Methylene Chloride Paint Removers, Protecting Public on 03/15/2019 (

It's about time. In approximately 1996, I testified regarding the devastating neurotoxic effects of methylene chloride on an individual consumer. It can be dangerous to consumers even in outdoor exposures, depending upon various conditions. It should not be sold to the average consumer.

It took more than 20 years for US EPA to opine: "In today’s final rule, EPA found risks to consumers to be unreasonable. Acute (short-term) exposures to methylene chloride fumes can rapidly cause dizziness, loss of consciousness, and death due to nervous system depression. People have died after being incapacitated during paint and coating removal with methylene chloride. A variety of effective, less harmful substitutes [is] readily available for paint removal."

2019: Appellate decision: Several times I have been asked to assist resolution of disability cases at the appellate level after the claimant had been denied compensation one or more times.  In a case decided last month regarding a USA veteran’s exposure to neurotoxicants at Marine Corp Base Camp Lejeune, the appellate judge overturned the previous denial of the veteran's benefits and awarded benefits based on my report. The judge wrote: "The most probative [meaning "affording proof or evidence"] opinion is a[n]... opinion by Dr. R. Singer (a neurotoxicologist, Ph.D.). This opinion of a doctor specializing in neuropsychology and trained in toxicology that it is as likely as not that the Veteran's disability is causally related to his service - and specifically to his presumed exposure to contaminated water while stationed at Camp Lejeune - is highly probative evidence supporting the claim. There certainly is no equally probative medical opinion to the contrary, so this claim must be granted.” This case resolution is a further advancement of the profession of applied neurotoxicology in the legal arena.