delivered the opinion of the court:
Defendants, Arco Petroleum Products Company (Arco) and Kenneth Roland, appeal from a jury verdict awarding $2 million in damages to the estate of Clearthis Knox. Defendants argue that the judgment should be reversed because they were prejudiced and denied a fair trial by erroneous rulings made in the trial court and by improprieties in plaintiff’s counsel’s impeachment of witnesses and in his closing arguments. In the alternative, defendants argue that the jury's award of damages was excessive and should be reduced.
Clearthis Knox, decedent, was killed on July 28, 1981, when his car collided with a tanker truck owned by Arco and driven by Roland. The accident occurred in Elk Grove Village at the intersection of Busse Highway and Marathon Road. Marathon Road is a private street leading to a Marathon oil terminal, which is used by Marathon and Arco drivers to refuel their tankers. In 1981, there were no traffic signals at the intersection but there was a stop sign on Marathon Road a few feet east of Busse.
On the night of the accident, Roland refueled his truck and left the Marathon terminal. Roland then began travelling west on Marathon Road, toward Busse Highway. Decedent, who was travelling north on Busse, struck Roland’s truck as it pulled into the intersection and crossed the northbound lanes of the highway. Decedent was killed instantly. An autopsy performed on decedent revealed a blood-alcohol level of .155, Vh times the legal limit, and a bile-alcohol level of .140.
On February 18, 1982, Edith Brown, administrator of decedent’s estate, filed this wrongful death action against defendants, seeking $1.5 million in damages. A jury found for plaintiff, returning a verdict *565in the amount of $2 million, but because the jury also found that plaintiff was 10% responsible for the accident, the verdict was reduced to $1.8 million.
In their appeal, defendants contend that the judgment should be reversed due to the number of trial errors that occurred and because of the many instances of improper conduct on the part of plaintiffs counsel.
It is well settled that a judgment should be reversed because of error only when it appears that the error affected the result of the trial. (Khatib v. McDonald (1980), 87 Ill. App. 3d 1087, 410 N.E.2d 266; Chloupek v. Jordan (1977), 49 Ill. App. 3d 809, 564 N.E.2d 650.) In reviewing a jury’s verdict, an appeals court need not determine that the record is free from error (Karsten v. McCray (1987), 157 Ill. App. 3d 1, 509 N.E.2d 1367); rather, the court need only determine whether any error occurred which operated to the prejudice of a party or which unduly affected the outcome (Karsten v. McCray (1987), 157 Ill. App. 3d 1, 509 N.E.2d 1367; Stromquist v. Burlington Northern, Inc. (1983), 112 Ill. App. 3d 37, 444 N.E.2d 1113; Chloupek v. Jordan (1977), 49 Ill. App. 3d 809, 564 N.E.2d 650). Our review of the verdict before us leads us to conclude that the trial court’s judgment must be reversed and remanded for a new trial.
Defendants have presented a long list of alleged errors and instances of improper conduct by plaintiff’s counsel. Defendants assert that the first instance of improper conduct occurred before trial, when plaintiff’s counsel asked a potential juror if he knew any of the 150 attorneys at defendant’s law firm. Defendants contend that their motion for a mistrial should have been granted since counsel’s statement was extremely prejudicial and suggested an unfair financial advantage on the part of defendants.
The transcript of the voir dire shows that at the start of jury selection, the trial court addressed the entire venire, asking them if they knew any of the parties or their attorneys. The court then questioned the jurors individually, asking each if he knew any of the parties, the attorneys, or their law firms. Thus, it is clear that plaintiff’s counsel’s statement served no purpose, except to draw attention to the size of defendants’ law firm, and was highly improper. However, an objection immediately was made by defendants’ counsel and, during a sidebar conference, the trial court instructed plaintiff’s counsel to refrain from making such remarks. Although we find no abuse of discretion in the trial court’s denial of defendants’ motion for a mistrial at this point (see Anderson v. Chesapeake & Ohio Ry. Co. (1986), 147 Ill. App. 3d 960, 498 N.E.2d 586; Benuska v. Dahl (1980), 87 Ill. *566App. 3d 911, 410 N.E.2d 249), we agree that the comment when combined with other errors that occurred in the proceedings served to deprive defendants of a fair trial.
Included among the errors alleged by defendants are the trial court’s action in allowing plaintiff’s counsel to question Arco’s maintenance superintendent, Richard Miriani, about the unavailability of maintenance and repair records relating to the accident; the court’s restriction of defendants’ cross-examination of Thad Aycock, plaintiff’s reconstruction expert, based on the Dead Man’s Act (Ill. Rev. Stat. 1981, ch. 110, par. 8—201); the court’s action in allowing plaintiff’s counsel to read into the record irrelevant matter from the statement of Anwar Younan, one of several witnesses who arrived on the scene shortly after the accident; and the court’s use of the Dead Man’s Act to exclude testimony by Kenneth Roland.
We find no error in plaintiff’s counsel’s cross-examination of Richard Miriani.
In Terracina v. Castelli (1979), 80 Ill. App. 3d 475, 400 N.E.2d 27, and Foerster v. Illinois Bell Telephone Co. (1974), 20 Ill. App. 3d 656, 315 N.E.2d 63, cases cited by defendants in support of their claim that the cross-examination was improper, this court held that defense counsel’s comments in closing arguments, implying that plaintiffs’ counsel had ulterior motives in failing to produce certain evidence, were improper and had no basis in the evidence. We find that these cases are inapplicable.
In the present case, Miriani testified on direct examination that Arco had a policy of retaining records for only a 12- or 13-month period. On cross-examination, plaintiff’s counsel questioned whether this policy also applied in cases of accidents, where it was possible that the records might be needed in the future. We believe counsel’s questions were reasonable, and we cannot agree with defendants’ assertion that the questions were intended to insinuate that Arco had intentionally destroyed material evidence.
However, on the issue of defendants’ questioning of plaintiff’s reconstruction expert, Thad Aycock, we agree with defendants’ contentions, and we find that the trial court improperly limited their cross-examination.
Defendants attempted to question Aycock about the materials he relied upon in reconstructing the accident. Following an objection by plaintiff, the trial court ruled that defendants could not ask whether Aycock considered statements made by Roland in reaching his conclusions.
An expert witness may disclose the underlying facts or data *567which form the basis for his opinion, even if this evidence is otherwise admissible. (See Wilson v. Clark (1981), 84 Ill. 2d 186, 417 N.E.2d 1322.) In Wilson, the supreme court pointed out that the burden is on an adverse party during cross-examination to elicit the facts underlying the expert opinion. 84 Ill. 2d at 194.
The dissent contends that “[i]t is improper for counsel to ask questions in front of the jury on cross-examination, which by innuendo may detract from a witness’ testimony, when there is no good-faith intention to follow up with proof of the facts to which counsel alludes,” and adds that “[t]he practice of offering matters in the presence of the jury that counsel knows to be inadmissible, in a manner calculated to elicit objections and create an appearance of concealment on the part of opposing counsel, must not be condoned.” 195 Ill. App. 3d at 580.
Here, however, defendants were not “offering matters,” they simply were trying to determine what information Aycock took into consideration in reaching his conclusions. While it is true that defendants could not read out specific statements in Roland’s deposition and ask whether Aycock considered each, defendants were entitled to inquire whether Aycock took the deposition into consideration. Further, if Aycock testified that he had considered the deposition, defendants were entitled to disclose to the jury the portions thereof that were considered.
Plaintiff contends that no error occurred because the record shows that Aycock did not consider Roland’s statement. This contention is based on a statement made during a sidebar conference by plaintiff’s counsel and, clearly, such a statement cannot be relied upon as establishing what materials Aycock considered in forming his opinions.
We find that the trial court also erred in allowing certain portions of Anwar Younan’s statement to be read into evidence. On direct examination, Younan testified that when he arrived at the scene of the accident, he saw no lights on the truck. On cross-examination, defendants’ counsel impeached Younan’s testimony with a prior statement made December 17, 1981, in which Younan said that the truck had lights on the bottom of the trailer and on each end, but none on the top. Defendants later called Raymond Eastridge, the court reporter who transcribed Younan’s December 1981 statement, to testify to the accuracy of the transcript. During plaintiff’s cross-examination of Eastridge, the trial court allowed plaintiff’s counsel to read into evidence a portion of Younan’s statement in which he said that “normally,” trucks would have lights on top. We agree with defendants’ *568contention that this was error.
Although plaintiff argues that the admission of this portion of Younan’s statement was necessary to place the other portions of the statement in context, we find that this was not the case. In a statement made six months after the accident, Younan claimed that the truck had lights on the bottom of the trailer and on each end. This statement was used at trial to impeach Younan’s testimony that he saw no lights on the truck when he arrived at the scene of the accident. Admission of the portion of the statement in which Younan said that trucks normally had lights on the top did not serve to complete or rehabilitate Younan’s testimony, nor did it alter the fact that Younan’s trial testimony was contradicted by his earlier statement. Rather, the statement served only to create the inference that Roland in some way had deviated from what was normal, and absent any foundation therefor, it was error to admit the statement.
Defendants’ next assertion of error concerns the trial court’s application of the Dead Man’s Act to limit the testimony of Kenneth Roland.
Prior to trial, the trial court granted a motion in limine filed by plaintiff, pursuant to the Dead Man’s Act, seeking to prohibit defendant Roland from testifying about anything that occurred after he left the Marathon terminal. Defendants contend that the trial court erred in using the Dead Man’s Act to restrict Roland’s testimony. They contend that plaintiff failed to provide any foundation in support of her motion to exclude Roland’s testimony, that the trial court’s application of the Act was too broad, and that Roland should have been allowed to testify regarding his actions as he drove down Marathon Road until he encountered decedent at the intersection.
The Dead Man’s Act provides that in the trial of any action in which any party sues or defends as the representative of a deceased person, no adverse person may testify on his own behalf to any conversation with the deceased or to any event which took place in the presence of the deceased. The purpose of the Act is to bar only that evidence which the deceased could have refuted. Malavolti v. Meridian Trucking Co. (1979), 69 Ill. App. 3d 336, 387 N.E.2d 426.
Here, the “event” in question is the accident, and it is clear that the trial court properly barred Roland from testifying concerning the details of the collision. In addition, in light of testimony at trial that the stop sign on Marathon Road was visible from Busse Highway, the trial court properly prevented Roland from testifying as to whether he stopped at the stop sign before.entering the intersection. However, statements in the record also indicated that the Marathon terminal *569was located at least one block from Busse Highway, and there was no evidence whatsoever that a person travelling northbound on Busse would be able to observe a vehicle leave the terminal, nor was there any evidence of when a vehicle travelling west on Marathon would be visible from Busse Highway. In the absence of evidence establishing that decedent would have observed and been able to testify to Roland’s actions before reaching the stop sign, it was error for the trial court to bar that portion of Roland’s testimony.
Although we find that the trial court’s application of the Act was too broad, we do not believe any prejudice resulted from the trial court’s action. What additional testimony Roland would have given to establish that he exercised due care had he not been precluded from testifying about his actions after leaving the terminal and before reaching the stop sign is not apparent from the record. However, Roland was allowed to testify concerning Arco’s maintenance and safety standards and as to his own safety inspections performed before and after each day’s shift. Roland also testified that there was a five-mile-per-hour speed limit on Marathon Road, which was strictly enforced, and that on the night of the accident, the lights on his truck were on before he left the Marathon terminal. Given the short length of time involved and the necessarily limited nature of the testimony Roland could have given, we do not believe the barred testimony would have materially affected the result. Ford v. City of Chicago (1985), 132 Ill. App. 3d 408, 476 N.E.2d 1232.
Defendants argue that the additional testimony was needed to dispel the impression created by improper testimony from one of plaintiff’s witnesses concerning the custom and usage of unspecified other truck drivers using Marathon Road. In the plaintiff’s case in chief, Willie Ridley, a friend of decedent’s, testified about the manner in which trucks leaving the Marathon terminal entered the Busse Highway-Marathon Road intersection. Defendants’ objection to the testimony was sustained and the testimony was stricken. However, plaintiff’s counsel subsequently made several more attempts to elicit testimony from Ridley about the manner in which trucks entered the intersection before the trial court finally instructed him to discontinue the line of questioning and admonished the jury to disregard the testimony. We agree that there was no foundation for Ridley’s testimony and we believe that counsel’s actions were an example of what the dissent refers to as “the practice of offering matters in the presence of the jury that counsel knows to be inadmissible, in a manner calculated to elicit objections and create an appearance of concealment on the part of opposing counsel.” 195 Ill. App. 3d at 580.
*570Defendants’ final assertions of error concern the cross-examination of their medical witnesses on the issue of decedent’s intoxication. Defendants contend that the trial court committed reversible error when it allowed plaintiff’s counsel to impeach the medical witnesses using materials that were not established as authoritative.
On two occasions during his cross-examination of Dr. Yuksel Konacki, the assistant medical examiner who performed the autopsy on decedent, plaintiff’s counsel read statements from an unidentified text and asked Konacki if he agreed with them. The statements read concerned “passive alcohol diffusion,” a theory that alcohol present in the stomach at death diffuses into adjacent tissues and organs, causing a high level of alcohol in those organs that is not representative of the level of alcohol present in circulating blood. When defendants objected to plaintiff’s counsel’s actions, the trial court noted that a lawyer could question an expert from a learned treatise and reserved its ruling pending some showing that there was a scientific opinion on the subject. Plaintiff’s counsel never identified the text to Konacki nor did counsel ask Konacki whether he considered the theory authoritative.
Subsequently, defendants filed a motion in limine seeking to prevent plaintiff from cross-examining witnesses from a text without identifying it and allowing the witness an opportunity to say that it was or was not authoritative. Although this motion was granted, plaintiff’s counsel, when cross-examining another medical witness, again read from a text and asked the witness if he agreed with what was read without identifying the text or allowing the witness to state whether he considered it authoritative.
In Darling v. Charleston Community Memorial Hospital (1965), 33 Ill. 2d 326, 211 N.E.2d 253, the Illinois Supreme Court stated that expert witnesses may be cross-examined as to their views of recognized authorities expressed in treatises or periodicals written for professional colleagues. The competence of the author of such a treatise or periodical can be established only by the testimony of a witness expert in the subject or by the trial judge taking judicial notice thereof. Darling, 33 Ill. 2d at 336.
In the present case, the materials used by plaintiff’s counsel in cross-examining defendant’s medical witnesses were never identified, the witnesses were not questioned concerning the author’s competence, judicial notice was not taken of the author’s competence, and plaintiff called no witnesses of her own to establish that the materials were authoritative. Therefore, it was error to permit the use of the materials. See People v. Behnke (1976), 41 Ill. App. 3d 276, 353 *571N.E.2d 684.
This error was compounded when the trial court, over defendants’ objections, allowed plaintiff’s counsel to argue the passive alcohol diffusion theory in his summation before the jury. Plaintiff presented no witnesses to establish that passive alcohol diffusion was possible, and the only evidence of the theory was the statements read by plaintiff’s counsel from the unidentified text during his cross-examination of Dr. Konacki.
Further, when plaintiff’s counsel cross-examined two other medical witnesses about the passive alcohol diffusion theory, one replied that there was no scientific data to support the theory and that he did not consider it authoritative. The other witness stated that the hypothesis was not well received in the scientific and medical community.
In light of plaintiff’s failure to present any evidence establishing the theory, we find that it was error for the trial court to allow plaintiff’s counsel to argue the theory in his closing arguments.
Defendants argue that the cumulative effect of this and the other errors that occurred during the proceedings served to deprive them of a fair trial. We agree. We also agree that the record fails to provide a basis for the jury’s $2 million award and that the errors occurring at trial may have resulted in the jury’s allocation of only 10% comparative negligence to decedent.
As we stated above, a judgment should be reversed because of error only when the error prejudices a party or unduly affects the outcome of the trial. (Khatib v. McDonald (1980), 87 Ill. App. 3d 1087, 410 N.E.2d 266; Chloupek v. Jordan (1977), 49 Ill. App. 3d 809, 564 N.E.2d 650.) In the present case, we believe the repeated attempts by plaintiff’s counsel to elicit improper testimony about the manner in which trucks using Marathon Road entered the intersection, the improper admission of the statement of Anwar Younan concerning what was “normal” for trucks, the failure of the trial court to allow defendants to cross-examine Thad Aycock concerning the basis for his expert opinion, the improper use by plaintiff’s counsel of unidentified authority to cross-examine medical witnesses, and counsel’s improper closing arguments resulted in prejudice to defendants.
On the issue of the amount of the damages awarded, it is well settled that the award of damages in a wrongful death action is within the discretion of the jury. (Flynn v. Vancil (1968), 41 Ill. 2d 236, 242 N.E.2d 237; Long v. Bennett (1978), 55 Ill. App. 3d 50, 370 N.E.2d 627.) However, the jury’s discretion is not without limitation. (Long v. Bennett (1978), 55 Ill. App. 3d 50, 370 N.E.2d 627.) In reviewing a *572jury’s award of damages, a court has an obligation to carefully scrutinize the record to determine whether the amount of the verdict is so large as to indicate passion and prejudice. Lau v. West Towns Bus Co. (1959), 16 Ill. 2d 442, 158 N.E.2d 63.
This action was brought on behalf of decedent’s parents, who live in Kansas City, and his married sister, who lives in Texas. When a wrongful death action is brought for lineal next of kin, the law presumes substantial pecuniary loss arising from the relationship alone. (Dotson v. Sears, Roebuck & Co. (1987), 157 Ill. App. 3d 1036, 515 N.E.2d 105.) In the present case, the jurors were informed of this presumption and told that it did not extend to decedent’s sister. The jurors were also instructed that in determining pecuniary loss they could consider money, goods, and services decedent had contributed to his survivors and was likely to have contributed in the future; decedent’s age, sex, health, and other personal characteristics; and the relationship between decedent and his parents.
While decedent’s sister did not testify, there was evidence that decedent enjoyed a normal, warm and loving relationship with his parents, that he visited them two to four times a year, that they exchanged gifts on Christmas and birthdays, and that decedent occasionally gave his parents cash gifts of $100 or less. Although this evidence served to buttress the presumption that decedent’s parents suffered substantial pecuniary loss upon the death of their child (see Ballweg v. City of Springfield (1986), 114 Ill. 2d 107, 499 N.E.2d 1373; Bullard v. Barnes (1984), 102 Ill. 2d 505, 468 N.E.2d 1228), we do not believe that it provided a sufficient basis for the jury’s verdict of $2 million. Given the lack of any evidence to support an award of this size, we must conclude the amount of the award indicates that it was the result of passion and prejudice. Lau v. West Towns Bus Co., 16 Ill. 2d at 453.
In conclusion, we find that the cumulative effect of the errors occurring at trial served to prejudice defendant. We also find that the record lacked any evidence justifying an award of $2 million and that the amount of the award precludes a finding that the errors occurring at trial did not affect both the jury’s award of damages and its allocation of negligence. Therefore, the judgment of the circuit court of Cook County is reversed and the cause remanded for a new trial.
Reversed and remanded.