DEB MEDALEN, Employee/Appellant, v. WASP, INC., and SELF-INSURED/BERKLEY RISK ADMIN. CO., Employer-Insurer, and BLUE CROSS/BLUE SHIELD, Intervenor.
WORKERS= COMPENSATION COURT OF APPEALS
SEPTEMBER 10, 2003
CAUSATION - SUBSTANTIAL CONTRIBUTING CAUSE. Substantial evidence, including expert medical and scientific opinions, supports the compensation judge=s finding that the employee=s exposure to paint was not a substantial contributing factor in the development of her basal cell carcinoma.
Determined by Rykken, J., Stofferahn, J., and Johnson, C.J.
Compensation Judge: Paul D. Vallant
MIRIAM P. RYKKEN, Judge
The employee appeals from the compensation judge=s finding that the employee=s work as a grinder and painter, including exposure to powder paint, did not substantially contribute to her basal cell carcinoma. We affirm.
Ms. Deb Medalen, the employee, first worked for Watkins Air Support Products, a/k/a WASP, Inc., the employer, in 1985, working six months on a part-time basis. Since 1988, she has worked for the employer on a full-time basis, with the exception of a layoff period between March 31 and July 11, 2002. Between 1988 and 1997, the employee worked as a grinder and painter. She used a metal grinder to grind welds in products to prepare them for painting, washed and dried parts, and painted the products. She alternated tasks, grinding parts one week and then painting the next, and estimated that during those weeks when painting she painted for an average of six hours per day.
Until early 1995, the employer used liquid paint in its plant. The employee wore protective gear when painting, including a cloth coverall (a clean one each day), respirator, safety glasses and a hood over her head. The employee testified that the liquid paint seldom landed on her head and face. In 1989 or 1990, the employee started working in a different building, at which time she began wearing an air hood.
In early 1995, the employer began using powder coat paint, a very fine powder that is shot from a gun and adheres to machine parts which are then baked to cure the paint. The employee used DuPont ASilver Horn II@ paint, approximately 50 percent of the time, which, according to its material safety data sheet (MSDS), contains triglycidal isocyanurate (TGIC), titanium dioxide, barium sulfate, chromium III and nickel metal. The employee also used ATiger@-Drylac paint, which contains TGIC, barium sulfate and titanium dioxide.
When she began using powder coat paint, the employee was provided with disposable coveralls and an airflow or air supply hood to wear while in the paint booth. Because the airflow hood was connected to an outside source of filtered air, the employee needed to remove her air hood each time she left the paint booth. The employee estimated that she exited the paint booth between six and twenty times daily, depending on the number of products she painted during a day and depending on how many times she had to switch paint. When she removed the hood, paint that had accumulated on the hood fell onto her hair, face, safety glasses and paint coveralls. The employee testified that the powdered paint often became airborne, that she often found paint on her hands, hair, face and glasses, and that the powder sifted through her coveralls and covered her body. For example, she testified that when she showered after the workday she noticed paint color on the floor of her shower, from the paint that had sifted through her coveralls.
In the spring of 1996, the employee developed a sore on the bridge of her nose, which appeared like a small scrape measuring approximately 1 centimeter in diameter. Her family physician, Dr. Mark Johnson, took a biopsy on March 14, 1997; that biopsy revealed basal cell carcinoma. Dr. Johnson referred the employee to Dr. Paul Heath, a plastic and reconstructive surgeon, who examined her on March 26, 1997, and stated in his chart note that
this lesion is a little bit unusual in appearance for usual skin cancer and [the employee] is also at a relatively young age to have such large skin cancer develop so quickly. In view of that I think it may be quite likely that the chronic irritation from paints at her place of employment has played a role in the development of this.
Dr. Heath recommended surgical excision of the sore which he performed on April 3, 1997. He recommended that the employee modify her exposure or change her duties to avoid further exposure to the paint products.
In a letter dated April 8, 1997, Dr. Heath summarized his opinions on the causation of the employee=s basal cell carcinoma, stating as follows:
It seems quite likely to me that the accumulation of paint particles around her nose piece combined with chronic irritation of the nose piece on her goggles would be a likely causative agent in this development of skin cancer in this relatively young patient. On reviewing the MSDS sheet on materials, it seems that the components of the silver horn II material are particularly problematic and, indeed, the acute and chronic health effects are both noted to show potential irritation as well as the potential for carcinogenesis. On that basis, I feel that her cancer is quite clearly work related.
On May 29, 1997, Dr. Heath stated that AI think that she should be very careful to avoid further contact with a paint that seemed to collect around her goggles in this area since I think there may be some connection, especially after reviewing the MSDS sheets.@ He also cautioned the employee to observe the area closely for any reoccurrence.
The employer, who was self-insured for workers= compensation liability, accepted primary liability and paid the employee=s temporary total disability benefits and medical expenses related to her surgery. After surgery, Dr. Heath restricted the employee from painting and advised her to wear sun screen all the time. The employee remained off work between April 3-17, 1997, and when she returned to work was assigned to hang and wash parts, and later to unload and package parts. Since July 2002 the employee has worked in the shipping department, assembling parts for shipping.
In August or September 2001, the employee developed another small sore adjacent to the location of her prior lesion, approximately 16 millimeters in diameter. Dr. Heath removed the lesion on November 21, 2001, and again diagnosed it as recurrent basal cell carcinoma. The employee arranged to have this second surgery during the Thanksgiving holiday and therefore only missed one day of work. The employer denied liability for treatment for medical expenses related to the employee=s recurrent injury in 2001. On March 29, 2002, the employee filed a medical request, requesting payment of expenses, totaling approximately $860.00, related to medical treatment received and reimbursement of her out-of-pocket- expenses. Blue Cross/Blue Shield of Minnesota intervened for reimbursement of medical expenses paid in the amount of $498.59.
At the employee=s request, Terry Martinez, Ph.D., pharmacologist, conducted a toxicology study of the paints used by the employee. He reviewed the employee=s deposition testimony, medical records, and material data sheets for the paint products, and researched the toxic effects of the chemicals contained in those paints. Dr. Martinez prepared a report dated March 14, 2002, in which he provided his opinion that the most probable cause of the employee=s basal cell carcinoma on her nose was the workplace exposure to powdered paint, and specifically the Silver Horn II and Tiger-Drylac paints. He concluded that the powdered paint products contained Aknown sensitizers, irritants, and carcinogen: specifically triglycidyl isocyanurate, chromium and nickel.@
The record also contains a report from Jordan Holtzman, M.D., Ph.D., pharmacologist, dated May 13, 2002, in which Dr. Holtzman reports on whether ingredients in paint products could have initiated the development of basal carcinomas on the plaintiff=s nose. Based on his research of the various chemical ingredients in the paints, Dr. Holtzman concluded that none of the ingredients had any carcinogenic potential and instead concluded that the most likely cause of the employee=s cancer was exposure to sun light. He stated that the most common cause of basal cell carcinomas is excessive exposure to the ultraviolet light present in sun light and that the employee=s skin biopsy indicated microscopic evidence of skin damage from excess exposure to ultraviolet light.
On August 15, 2002, Dr. Steven Prawer, a dermatologist with a sub-speciality in occupational dermatology, examined the employee at the request of the self-insured employer. Based upon his review of the employee=s medical records, the reports prepared by Drs. Martinez and Holtzman, and the history taken from the employee, Dr. Prawer concluded that the employee=s work environment did not contribute to the development of her basal cell carcinoma, nor did it aggravate or accelerate the occurrence of the disease diagnosed in 1997 nor accelerate the recurrence in 2001. Instead, Dr. Prawer concluded that the employee=s basal cell carcinoma was caused by exposure to sunlight, basing this conclusion on the exposure to sunlight the employee experienced during her childhood and young adulthood while living on a farm. He explained that the biopsy taken in 1997 showed basal cell carcinoma with dermal actinic damage caused by sun penetration through the upper layer of the skin epidermis, which affected the lower portion of the skin dermis, and that the biopsy taken in 2001 showed ulceration and marked solar elastosis (sun damage) of dermal collagen. On examination, Dr. Prawer also noted that the employee had several brown macules on her arms, hands, upper back and upper chest, identified as Asolar lentigines@ which are a sign or chronic sun exposure and that the employee also had manifested telangiectasia (enlarged capillaries) on the bridge of her nose, resulting from solar damage. In Dr. Prawer=s opinion, the chronic irritation on the bridge of the employee=s nose caused by wearing safety glasses, and her exposure to chemicals contained in the powder coating paint, did not contribute to the development to her basal cell carcinoma.
The self-insured employer also obtained a toxicology report from Jeffrey Stevens, Ph.D., toxicologist, dated October 21, 2002. Based upon Dr. Stevens=s review of the employee=s deposition testimony, the toxicity profiles and material data sheets describing the chemicals contained in the paints that the employee used and reports of epidemiological studies done on those chemical components, Dr. Stevens concluded that the paint to which the employee was exposed did not cause her skin cancer. Dr. Stevens focused on three constituents or components of the paints, chromium, nickel and triglycidyl isocyanurate (TGIC). Dr. Stevens advised that the only paint that the employee used that contained chromium was Silver Horn II, which contains chromium III. He stated that airborne chromium III exposure has never been associated with any type of cancer and that only chromium IV has been associated with respiratory system cancers when exposure has been through the air. Dr. Stevens concluded that Silver Horn II was the only paint product identified that contains nickel, and that the form of nickel present, metallic nickel, has not been associated with cancer. He explained that only exposure to other forms of nickel can lead to respiratory system cancers. He also stated that the typical latency period, between exposure and development of symptoms, is typically five years for nonmetallic forms of nickel and ten years for chromium IV.
Dr. Stevens also concluded that TGIC has not been associated with cancer in any workplace to date. Dr. Stevens also opined that the three chemical constituents in the powdered paint products used by the employee did not Achemically promote or increase Ms. Medalen=s risk of skin cancer from another agent, e.g., UV light (sun light).@ He concluded that although one or more of those three chemicals in the paints might have contributed to the localized irritation on the employee=s nose, with a primary mechanism likely being her goggles, that Athis acute irritation per se is not likely to have >sensitized= the area to cancer induction by UV irradiation, which is the most likely cause of her skin cancer.@
A hearing was held on December 14, 2002, to address the employee=s medical request. In Findings and Order, served and filed January 15, 2003, the compensation judge denied the employee=s claim for payment of medical expenses, concluding that the employee=s work activities were not a substantial contributing cause of either the basal cell carcinoma excised on April 3, 1997, nor the recurrent basal cell carcinoma excised on November 21, 2001. The compensation judge further found that the employer=s prior payment of workers= compensation benefits, related to the employee=s 1997 surgery, were paid under mistake of fact. The employee appeals.
STANDARD OF REVIEW
On appeal, the Workers' Compensation Court of Appeals must determine whether "the findings of fact and order [are] clearly erroneous and unsupported by substantial evidence in view of the entire record as submitted." Minn. Stat. ' 176.421, subd. 1 (1992). Substantial evidence supports the findings if, in the context of the entire record, "they are supported by evidence that a reasonable mind might accept as adequate." Hengemuhle v. Long Prairie Jaycees, 358 N.W.2d 54, 59, 37 W.C.D. 235, 239 (Minn. 1984). Where evidence conflicts or more than one inference may reasonably be drawn from the evidence, the findings are to be affirmed. Id. at 60, 37 W.C.D. at 240. Similarly, findings of fact should not be disturbed, even though the reviewing court might disagree with them, "unless they are clearly erroneous in the sense that they are manifestly contrary to the weight of the evidence or not reasonably supported by the evidence as a whole.@ Northern States Power Co. v. Lyon Food Prods., Inc., 304 Minn. 196, 201, 229 N.W.2d 521, 524 (1975).
The employee appeals from the compensation judge=s finding that the employee=s work activities were not a contributing cause of her basal cell carcinoma. The employee relies upon the expert medical opinions of Dr. Paul Heath, who is board certified in general surgery, plastic and reconstructive surgery, and who concluded that the employee=s exposure to powder paint was a contributing factor to the development of the employee=s basal cell carcinoma. The employee contends that the compensation judge=s findings should be reversed, because those findings were based on opinions of medical and scientific experts whose opinions lacked proper foundation. The employee specifically argues that the medical opinions provided by the employer=s experts contained two foundational errors. She argues that those experts inaccurately assumed that the employee previously had experienced prolonged sun exposure when she resided on a farm. She also argues that each of the employer=s experts failed to address the theory of causation provided by Dr. Heath, that is, that the employee developed a sore on the bridge of her nose from the powder paint rubbing on the nose piece of her safety glasses, and that over time the sore was opened, providing the paint chemicals with direct access to the underlying basal cells in the employee=s nose. In addition, the employee argues that the employer=s experts inappropriately determined that the relatively short period of time when the employee was exposed to powder paint was too short a latency period for cancer to develop from exposure to that paint. The employee further argues that the compensation judge applied the wrong legal standard in requiring her to prove that her work exposure to paint was the sole cause of her basal cell carcinoma. She argues that she met her burden of proving that her exposure at work was Aa@ substantial contributing cause of her carcinoma.
As stated by the Minnesota Supreme Court, AThe competency of a witness to provide expert medical testimony depends upon both the degree of the witness= scientific knowledge and the extent of the witness= practical experience with the matter which is the subject of the offered testimony.@ Reinhardt v. Colton, 337 N.W.2d 88, 93 (Minn. 1983), as cited in Drews v. Kohl=s, 55 W.C.D. 33 (W.C.C.A. 1996), summarily aff=d (Minn. July 12, 1996). Adequate foundation is necessary for a medical opinion to be afforded evidentiary value. Winkles v. Independent Sch. Dist. No. 625, 46 W.C.D. 44, 58 (W.C.C.A. 1991). To establish an adequate foundation, the facts upon which an expert relies for his or her opinions must be supported by the evidence. McDonald v. MTS Sys. Corp., 43 W.C.D. 83 (W.C.C.A. 1990), summarily aff=d (Minn. July 13, 1990).
In the present case, the employee alleges that the opinions of Drs. Prawer, Stevens and Holtzman are based on an inaccurate assumption that the employee sustained prolonged exposure to sunlight while residing on a farm during her childhood and early adulthood. The employee testified, and also reported to physicians, that her exposure to sunlight was limited, since she primarily performed housework and child care chores as opposed to outdoor farm work. She acknowledged that although she assisted her mother with a vegetable garden during her childhood and also tended a garden in later years, this work was performed in the morning and evening hours which limited her exposure to sunlight. She also testified that she recalled experiencing no sunburn between the ages of 6 and 18, and recalled only one sunburn on her legs during her adult years.
Of the three employer experts, Dr. Prawer discussed sunlight exposure the most. He based his opinion on his review of the employee=s medical records, the history provided by the employee, his findings from the physical examinations he conducted on the employee, and his review of the material safety data sheets, reports from Dr. Terry Martinez, clinical toxicologist and materials submitted by Dr. Holtzman, pharmacologist. Dr. Stevens did not mention the extent of sun exposure the employee may have experienced, but instead focused on lack of toxicity of the paint chemicals. Dr. Holtzman also focused on the carcinogenic potential of the chemicals and concluded that the most likely cause of the employee=s carcinoma was sun light exposure, based on the biopsy results.
Based on their professional experience and educational background in dermatology, toxicology and pharmacology, Drs. Stevens, Prawer and Holtzman all clearly had Apractical experience with the matter@ at issue. See Jepsen v. Bayliner Marine Corp., 55 W.C.D. 370 (W.C.C.A. 1996) summarily aff=d (Minn. Oct. 29, 1996). The employee=s concerns about their focus on the employee=s exposure to sunlight, and their determination that this was a cause of her basal cell carcinoma, call into question neither the degree of the doctors= knowledge nor the extent of their experience. See Drews, 55 W.C.D. at 39; Reinhardt, 337 N.W.2d at 93. Although these concerns may relate to the persuasiveness or weight accorded Drs. Prawer, Stevens and Holtzman, they do not demonstrate an inadequate factual foundation for the doctors= opinions. See also McDonald, 43 W.C.D. 83; Stuhr v. Northwestern Travel Serv., Inc., 57 W.C.D. 352 (W.C.C.A. 1997) (citing Bossey v. Parker Hannifin, slip op. (W.C.C.A. Mar. 14, 1994)), summarily aff=d., (Minn. Dec. 15, 1997).
The employee also contends that the employer=s experts failed to address the basic theory of causation given by Dr. Heath, that is, that the combination of the safety glasses sitting on the bridge of her nose at work and the corrosive nature of the powdered paint caused a open sore on the employee=s nose that allowed the paint chemicals to come into direct contact with the underlying basal cells. Dr. Prawer generally addressed this issue in his deposition; he testified that even if he assumed that the powder paint was in contact with an open sore on the employee=s nose over a period of eight or nine months, he believed the paint would not have caused changes in the employee=s skin in such a short period of time. In addition, Dr. Stevens discussed the issue of skin irritation and whether topical application of chemicals would have promoted basal cell carcinoma. Dr. Stevens referred to studies indicating that if applied topically, chromium and nickel do not have the ability to enter skin cells and therefore cannot Asensitize@ cells to another agent. Dr. Stevens concluded that topical application of these chemicals to skin cells has no effect, promotional or inhibitory, on skin tumor induction, and also stated that ATGIC when administered topically to the skin concomitantly with a known skin carcinogen actually showed an inhibitory effect on cancer induction.@ While we note that the employer=s experts did not specifically refer to Dr. Heath=s causation opinion, we do not regard that as a foundational defect which should result in exclusion of their opinions.
The compensation judge weighed the conflicting expert medical and scientific opinions and determined that testimony of Drs. Prawer and Stevens was more persuasive than that of Drs. Heath and Martinez, and also determined that Dr. Holtzman=s opinion buttressed the employer=s arguments. While there is evidence to the contrary on the issue of causation, including the employee=s testimony and the opinions and testimony of Drs. Heath and Martinez, we cannot conclude that the compensation judge erred in accepting the opinions rendered by the employer=s medical and scientific experts on this issue. See Nord v. City of Cook, 360 N.W.2d 337, 342-43, 37 W.C.D. 364, 372-73 (Minn. 1985). In addition, as stated by the supreme court,
[U]ntil the time comes when medical knowledge has progressed to such a point that experts in the field of medicine can agree, causal relation in determining compensable injury or disease will have to remain in the province of the trier of fact. Where qualified medical witnesses differ as they do here, it ordinarily is not for us on appeal to say that one is so eminently right and the other so clearly wrong that the fact finder was obliged to accept the opinion of one and discard the opinion of the other.
Kelly v. C.M.I. Refrigeration, 231 N.W.2d 490, 491, 27 W.C.D. 951, 952 (Minn. 1975)
(citing Golob v. Buckingham Hotel, 244 Minn. 301, 69 N.W.2d 636, 18 W.C.D. 275 (1955)).
Concluding that the opinions of Drs. Prawer, Stevens and Holtzman are adequately founded, we uphold the compensation judge=s decision to rely on them, and affirm the decision of the compensation judge.