Castillon vs. Magsaysay Mitsui Osk Marine, Inc. et al.

Work-relatedness for a seafarer's illness requires only a reasonable link between the illness and the seafarer's work, not sole causation; illnesses not listed under Section 32-A of the POEA-SEC are disputably presumed work-related, and a quitclaim is invalid where the consideration is less than the seafarer's legal entitlement and the execution is not voluntary.

Junlou H. Castillon was employed by Magsaysay Mitsui Osk Marine, Inc. as an Able Seaman under a Philippine Overseas Employment Administration Standard Employment Contract, with MOL Ship Management Co., Ltd. as the principal and Francisco D. Menor impleaded as respondent. The contract governs compensation for work-related illness or death, lists occupational diseases under Section 32-A, and provides under Section 20(A)(4) that illnesses not listed under Section 32 are disputably presumed work-related. The dispute concerns whether Castillon's colon cancer and subsequent death are compensable and whether a quitclaim he signed before a labor arbiter bars the claim.

Junlou H. Castillon was employed by Magsaysay Mitsui Osk Marine, Inc. as an Able Seaman for nine (9) months with a basic salary of US$564.00. He underwent a pre-employment medical examination and was declared fit to work. On February 23, 2009, he was deployed on board M/V Amethyst Ace.

In June 2009, Castillon complained of intermittent mild stomach pains but dismissed them as ordinary discomfort. By August 2009, the stomach ache became severe and he discovered blood in his stool. While in Japan, a doctor examined him, declared him unfit for duty, and recommended his repatriation, along with laboratory tests to rule out malignancy due to his record of chronic hemorrhage and family history of intestinal malignancy. On September 3, 2009, he was repatriated to the Philippines. He reported his condition to Magsaysay, which referred him to Medicross Health Management Hospital, where he was diagnosed with an abdominal mass and recommended to undergo colonoscopy. The company-designated physician determined that Castillon's condition was not work-related. Castillon then underwent colonoscopy and biopsy tests at Iloilo Doctors Hospital, which showed lymph nodes in his colon, resulting in Sigmoid Colon Carcinoma Stage III.B; he was endorsed for immediate operation.

Castillon called the Claims Department of Magsaysay and informed them of the needed operation. Magsaysay provided an estimated operation cost of P100,000.00. On November 3, 2009, Castillon was admitted to Iloilo Doctors Hospital, where Dr. Maximo Nadala conducted the operation and subsequently endorsed Castillon for chemotherapy. On December 12, 2009, Castillon asked for a quotation of expenses for chemotherapy and sent Magsaysay a request for financial assistance.

On August 26, 2010, Magsaysay asked Castillon to go before the National Labor Relations Commission in Quezon City. Castillon signed a pro-forma labor complaint against Magsaysay, which was assigned to Labor Arbiter Melquiades Sol Del Rosario. Immediately after, Castillon signed a quitclaim and received a check for P888,340.00 before Labor Arbiter Del Rosario. The quitclaim stated that, in exchange for TWENTY THOUSAND US DOLLARS, he released Magsaysay, MOL Ship Management Co., Ltd., and others from all claims on account of his illness, described as Colonic Carcinoma Sigmoid Stage IV with Urinary Bladder Invasion; the document was translated into Filipino and contained handwritten answers by Castillon. Labor Arbiter Del Rosario issued an order of dismissal with prejudice that same day.

On October 1, 2010, after reflecting on what had transpired, Castillon filed a complaint against Magsaysay for claim of disability and other benefits. On May 5, 2011, the Labor Arbiter dismissed the case for lack of merit, and his motion for reconsideration was denied. The NLRC dismissed his appeal, ruling that the order of dismissal with prejudice operated as res judicata; it noted that the quitclaim was in the vernacular and that a Joint Motion to Dismiss attested to the full settlement. The Court of Appeals likewise dismissed the petition and affirmed the NLRC, finding that the quitclaim was knowingly and voluntarily executed, that the Affidavit of Claimant stated the US$20,000.00 covered all benefits due under the POEA-SEC, that the document was translated and signed in both English and Filipino versions, and that the amount was fair and reasonable because the illness was not work-related. Castillon moved for reconsideration, but it was denied; during its pendency, he died. His widow and two children then filed the Petition for Review on Certiorari. The labor tribunals and the Court of Appeals relied on the company-designated physician's finding that the illness was not work-related; the Supreme Court noted that Castillon alleged poor dietary provisions of canned goods high in fat and cholesterol, work of more than eight hours, and exposure to oils and fumes, which respondents did not specifically deny.

• Voluntariness of Quitclaim: Petitioners argued that Castillon's execution of the quitclaim could not be considered voluntary because he was already weak and in dire need of financial assistance, placing him in a disadvantageous position when he signed it.
• Adequacy of Consideration: Petitioners maintained that a quitclaim is not valid if the compensation is less than what the claimant is legally entitled to; Castillon was entitled to more than what respondents gave, including chemotherapy costs of P313,125.00, doctor's professional fees of P400,000.00, sickness allowance for four (4) months of US$2,256.00, and full disability benefits of US$60,000.00, making P888,340.00 unfair and unreasonable.
• Work-Relatedness: Petitioners argued that Castillon's illness was work-related because he was declared fit to work before boarding, was diagnosed during the term of his contract, and the nature of his job aggravated his condition; his work was stressful and his meals on board were always canned goods, mostly high in fat.
• Company-Designated Physician's Findings: Petitioners contended that the company-designated physician's finding that the illness was not work-related should be given scant consideration because the physician was respondents' chosen doctor and the findings were self-serving and biased.
• Res Judicata and Fraud: Petitioners argued that there was no res judicata because the proceedings before Labor Arbiter Del Rosario were fraudulent; the pro-forma complaint and hurried dismissal with prejudice were orchestrated to take advantage of Castillon, who was a layman not well-versed in legal matters, and it was Magsaysay that directed him to sign a prepared pro-forma complaint only to cause its immediate dismissal with prejudice.
• Reply on Work Conditions: In reply, petitioners added that even assuming the pre-employment medical examination was not exploratory, Castillon fell ill during the term of his contract and his illness was aggravated by his work; he worked more than eight (8) hours, lifted heavy objects, and was exposed to oils and fumes, and it was questionable why respondents paid US$20,000.00 while insisting the ailment was not work-related.

• Non-Compensability: Respondents countered that Castillon's illness is not compensable under the POEA-SEC because it is not work-related; being declared fit to work prior to boarding and later getting sick on board does not make the illness work-related.
• Section 32-A Occupational Diseases: Respondents averred that to be regarded as work-related, the illness must be one of those enumerated as occupational diseases under Section 32-A of the POEA-SEC; the company-designated physician determined that the illness was not work-related, and this finding was never disputed by contrary evidence.
• Pre-Employment Medical Examination: Respondents argued that the pre-employment medical examination is merely routinary and not exploratory, and is not conclusive proof of work-relatedness.
• Working Conditions and Diet: Respondents disputed petitioners' claim that working conditions and unhealthy diet on board contributed to the illness, arguing that the claim is baseless because there is a prevailing standard on dietary provisions on board vessels and petitioners failed to present evidence that Castillon's work aggravated his illness.
• Validity of Quitclaim: Respondents argued that the quitclaim signed by Castillon is a valid settlement of his claims; Castillon knew the payment was the full and complete settlement of all his claims, the document was translated to Filipino, he voluntarily acknowledged it before a Notary Public and confirmed it before the Labor Arbiter, and petitioner Daisy Castillon signed as a witness.
• Res Judicata: Respondents argued that the dismissal of the first case constituted res judicata, with the four elements present: the dismissal order from Labor Arbiter Del Rosario is final; the order was issued after considering documentary evidence; the NLRC had jurisdiction over the claim and the parties; and there is an identity of parties, subject matter, and cause of action in the first and second cases.

• Questions of Fact in Rule 45: Whether petitioners may raise questions of fact in a Rule 45 petition.
• Disability or Death Benefits: Whether petitioners may claim disability or death benefits against respondents.
• Company-Designated Physician's Findings: Whether the findings of the company-designated physician must be upheld.
• Work-Relatedness: Whether Castillon's illness is work-related.
• Validity of Quitclaim: Whether the quitclaim signed by Castillon was valid.
• Res Judicata: Whether the order of dismissal operates as res judicata.

• Questions of Fact in Rule 45: Yes, by exception. Although Rule 45 generally limits review to questions of law, the Court may delve into questions of fact where the Court of Appeals overlooked relevant and crucial facts, as in this case.
• Disability or Death Benefits: Yes. Death benefits are compensable because work-relatedness and death during the term of employment were established under the POEA-SEC.
• Company-Designated Physician's Findings: No, not necessarily. The company-designated physician's assessment was incomplete and not final or definitive, having been made before the colonoscopy and biopsy, and cannot be given credence.
• Work-Relatedness: Yes. Colon cancer is not listed under Section 32-A, so it is disputably presumed work-related; respondents failed to rebut the presumption, and Castillon's working conditions contributed to or aggravated his illness.
• Validity of Quitclaim: No. The consideration was less than Castillon's legal entitlement and the quitclaim was not voluntarily executed; it is invalid as contrary to public policy.
• Res Judicata: No. Although a quitclaim has the effect of res judicata, an invalid quitclaim contrary to public policy cannot bar recovery of the full benefits.

• Questions of Fact in Rule 45: Rule 45, Section 1 limits petitions for review to questions of law, and factual findings of quasi-judicial agencies like the NLRC, when affirmed by the Court of Appeals, are generally conclusive. However, exceptions allow review of facts when the Court of Appeals manifestly overlooked facts that would justify a different conclusion, when evidence is insufficient, or when too much is concluded from bare or incomplete facts. The Court found that the Court of Appeals and labor tribunals overlooked relevant and crucial facts, so it proceeded to resolve the factual questions.

• Disability or Death Benefits: Under Section 20(B)(1) of the POEA-SEC, death is compensable if it is work-related and occurred during the term of the employment contract. Work-relatedness requires a reasonable linkage between the disease and the seafarer's work; the work need not be the sole contributor or factor in the aggravation of the illness. Section 20(A)(4) provides that illnesses not listed under Section 32 are disputably presumed work-related. Colon cancer is not among the occupational diseases listed under Section 32-A, so it is disputably presumed work-related, shifting the burden to respondents to prove otherwise. The company-designated physician's finding that the illness was not work-related was not final and definitive because it was made after merely feeling an abdominal mass and recommending a colonoscopy, before the colonoscopy and biopsy established the diagnosis. Petitioners proved that Castillon's working condition contributed to or aggravated his illness: he was provided canned goods high in fat and cholesterol, worked more than eight hours, and was exposed to oils and fumes, allegations respondents did not specifically deny. Leonis Navigation Co., Inc. vs. Villamater recognized that colon cancer can be work-related if conditions inside the vessel increased or aggravated the risk. Family history and genetics may contribute, but the seafarer's work need not be the sole cause; only reasonable proof of work connection, not direct causation, is required. The presumption of work-relatedness is not a presumption of compensability, but petitioners established the conditions for compensability. Thus, death benefits under Section 20(B)(1) and burial expenses under Section 20(B)(4)(c) are due.

• Company-Designated Physician's Findings: The POEA-SEC gives the company-designated physician primary responsibility to determine disability grading or fitness to work, and the rules favor that assessment because the physician has closely monitored and treated the seafarer. However, courts are not automatically bound; the assessment must be complete, definite, and final to reflect the true extent of the illness. Tardy, incomplete, and doubtful medical assessments, even if issued by a company-designated physician, are disregarded. Here, the company-designated physician declared the illness not work-related before the colonoscopy and biopsy tests were conducted, when there was no accurate diagnosis yet. The assessment was therefore incomplete and inconclusive and cannot be the basis for denying compensability.

• Work-Relatedness: Work-relatedness does not require that the seafarer's work be the main cause of the illness's progression or that the illness drastically progressed during employment. The severity and progression of the illness is not the test; it is enough that the work contributed to the establishment or, at the very least, aggravation of a pre-existing condition. Castillon's poor dietary provisions and exposure to oils and fumes worsened his condition, consistent with jurisprudence recognizing that high fat intake and an obnoxious working environment increase the risk of colon cancer. Respondents never denied these working conditions; they merely relied on the incomplete company-designated physician's findings. While family history and other factors may contribute, not all factors need be work-related, and the employment need only contribute even in a small degree. Only probability, not ultimate certainty, is required. The disputable presumption of work-relatedness also shifted the burden to respondents, which they failed to discharge.

• Validity of Quitclaim: The law frowns upon quitclaims executed by employees as contrary to public policy, but a quitclaim is valid and binding when executed voluntarily, with full understanding of its terms, and for a reasonable consideration. The requisites are: (1) the employee executes the quitclaim voluntarily; (2) there is no fraud or deceit; (3) the consideration is credible and reasonable; and (4) the contract is not contrary to law, public order, public policy, morals, or good customs, or prejudicial to a third person with a right recognized by law. The employer bears the burden of proving that the quitclaim is a reasonable settlement and was executed voluntarily with full understanding. Here, the consideration of US$20,000.00 was less than the US$65,000.00 to which petitioners were legally entitled, and Castillon had already progressed to stage 4 colon cancer and was desperate for financial assistance for chemotherapy when he signed, leaving him in no position to bargain. The quitclaim is therefore invalid as contrary to public policy.

• Res Judicata: A quitclaim has the effect and authority of res judicata upon the parties, but it may be rendered null and void when found contrary to public policy. Because the quitclaim was invalid for inadequate consideration and involuntariness, respondents cannot cite res judicata to bar petitioners from claiming the full value of the benefits. Attorney's fees are also warranted because this is an action for employer's liability under Article 2208(8) of the Civil Code. Social justice demands that seafarers' families receive what they are due.

• Work-Relatedness in Seafarer Claims — Work-relatedness for a seafarer's illness requires only a reasonable link between the illness and the seafarer's work; it is not required that the work be the sole contributor or factor in the aggravation of the illness. The test is reasonable proof of work-connection, not direct causation. The Court applied this standard in finding Castillon's colon cancer work-related because his working and living conditions contributed to or aggravated it.

• Disputable Presumption of Work-Relatedness under Section 20(A)(4) of the POEA-SEC — Illnesses not listed under Section 32 of the POEA-SEC are disputably presumed work-related. The presumption shifts the burden to the employer to prove that the illness was pre-existing or that the work did not contribute to or aggravate it; if the employer contests work-relatedness, the burden shifts back to the seafarer to prove otherwise and to comply with the conditions of compensability. The Court applied this to colon cancer, which is not listed under Section 32-A, and found respondents failed to rebut the presumption.

• Compensability Requirements under Section 32-A of the POEA-SEC — For an occupational disease and the resulting disability or death to be compensable, all of the following must be satisfied: (1) the seafarer's work must involve the risks described; (2) the disease was contracted as a result of exposure to the described risks; (3) the disease was contracted within a period of exposure and under such other factors necessary to contract it; and (4) there was no notorious negligence on the part of the seafarer. Even if the illness is not contracted as a result of exposure to the work's risks, a pre-existing illness may be work-related if aggravated by the seafarer's working conditions. The Court found these conditions satisfied through the work-relatedness of Castillon's colon cancer.

• Company-Designated Physician's Assessment — The company-designated physician has primary responsibility to determine the seafarer's disability grading or fitness to work, and the assessment is favored because the physician has monitored and treated the seafarer. However, the assessment must be complete, definite, and final; tardy, incomplete, and doubtful assessments are disregarded. The Court disregarded the company-designated physician's finding because it was made before the colonoscopy and biopsy and was not a final or definitive diagnosis.

• Validity of Quitclaims — The law frowns upon quitclaims executed by employees, but a quitclaim is valid and binding if: (1) the employee executes it voluntarily; (2) there is no fraud or deceit; (3) the consideration is credible and reasonable; and (4) the contract is not contrary to law, public order, public policy, morals, or good customs, or prejudicial to a third person with a right recognized by law. The employer bears the burden of proving these requisites. The Court invalidated Castillon's quitclaim because the consideration was less than his legal entitlement and it was not voluntarily executed.

• Res Judicata and Invalid Quitclaims — A quitclaim has the effect and authority of res judicata upon the parties, but it may be rendered null and void when found contrary to public policy. An invalid quitclaim cannot bar recovery of the full measure of a worker's benefits and rights. The Court held that respondents could not invoke res judicata because the quitclaim was invalid.

• Attorney's Fees in Employer's Liability Actions — Under Article 2208(8) of the Civil Code, attorney's fees may be recovered in actions for indemnity under workmen's compensation and employer's liability laws. The Court awarded attorney's fees equivalent to 10% of the total monetary award.

• Social Justice in Labor Cases — Social justice is part of every decision in labor cases; seafarers work under conditions controlled by the vessel's officers and owners, and fairness demands that their families receive what they are due. The Court invoked this principle in granting the full benefits.

• "In resolving claims under the Philippine Overseas Employment Administration Standard Employment Contract, the element of work-relatedness only demands a reasonable link between the illness and the seafarer's work. It is not required that the seafarer's work is the sole contributor or factor in the aggravation of the illness. The test is only reasonable proof of work-connection, and not direct causation." — This passage states the core standard for work-relatedness, rejecting direct causation and requiring only a reasonable link between the illness and the seafarer's work.

• "Those illnesses not listed in Section 32 of this Contract are disputably presumed as work-related." — This provision, quoted from Section 20(A)(4) of the POEA-SEC, establishes the disputable presumption that made colon cancer work-related and shifted the burden to respondents.

• "Here, the quitclaim signed by Castillon cannot be regarded as valid and binding. First and foremost, the consideration for the settlement of Castillon's claim is less than what he is legally entitled to. The amount of US$20,000.00 given by the respondents is hardly sufficient considering that the petitioners are legally entitled to a total amount of US$65,000.00." — This passage is the ratio for invalidating the quitclaim, grounding invalidity on inadequate consideration compared with the legal entitlement.

• "While a quitclaim has the effect and authority of res judicata upon the parties, a quitclaim may be rendered null and void when found contrary to public policy." — This passage explains why the dismissal and quitclaim did not bar recovery: an invalid quitclaim contrary to public policy cannot have res judicata effect.

• Fuji Television Network, Inc. vs. Espiritu, 749 Phil. 388 (2014) — Explained the procedural parameters for petitions for review in labor cases, including that Rule 45 generally limits review to questions of law and that factual findings of quasi-judicial agencies affirmed by the Court of Appeals are conclusive, subject to exceptions.
• Romana vs. Magsaysay Maritime Corp., 816 Phil. 194 (2017) — Held that the legal presumption of work-relatedness for unlisted illnesses is not a presumption of compensability; the seafarer must still prove compliance with Section 32-A, and the employer may controvert the presumption.
• Magsaysay Maritime Corporation vs. National Labor Relations Commission, 630 Phil. 352 (2010) — Illustrates that the employer may rebut the presumption of work-relatedness by showing that the working conditions could not have caused or increased the risk of the illness.
• Magsaysay Maritime Services vs. Laurel, 707 Phil. 210 (2013) — Held that the seafarer's work need not be the sole and only reason for the illness; a reasonable linkage between the disease and the work is sufficient.
• Leonis Navigation Co., Inc. vs. Villamater, 628 Phil. 81 (2010) — Recognized that colon cancer can be considered a work-related illness and that a seafarer is entitled to disability benefits if conditions inside the vessel increased or aggravated the risk of colon cancer.
• Skippers United Pacific, Inc. vs. Lagne, G.R. No. 217036, August 20, 2018 — Held that it is sufficient that the seafarer's employment contributed, even if only in a small degree, to the development of the disease.
• Jebsens Maritime, Inc. vs. Alcibar, G.R. No. 221117, February 20, 2019 — Repeatedly emphasized that working conditions and dietary provisions aggravate and increase a seafarer's risk of colon cancer.
• Orient Hope Agencies, Inc. vs. Jara, G.R. No. 204307, June 6, 2018, 864 SCRA 428 — Held that a final and definite disability assessment is necessary to reflect the true extent of the seafarer's sickness or injuries and to award commensurate benefits.
• Pastor vs. Bibby Shipping Philippines, Inc., G.R. No. 238842, November 19, 2018 — Held that the company-designated physician's medical assessment must be complete and appropriately issued; otherwise, the medical report shall be set aside and the disability grading disregarded.
• Toquero vs. Crossworld Marine Services, Inc., G.R. No. 213482, June 26, 2019 — Held that tardy, doubtful, and incomplete medical assessments, even if issued by a company-designated physician, are set aside.
• Radio Mindanao Network, Inc. vs. Amurao III, 746 Phil. 60 (2014) — Held that legitimate waivers representing voluntary and reasonable settlements of laborers' claims should be respected as the law between the parties where executed with full understanding and for credible and reasonable consideration.
• Goodrich Manufacturing Corporation vs. Ativo, 625 Phil. 102 (2010) — Enumerated the requisites for a valid quitclaim: voluntary execution, no fraud or deceit, credible and reasonable consideration, and not contrary to law, public order, public policy, morals, or good customs.
• Principe vs. Philippine-Singapore Transport Services, Inc., 257 Phil. 522 (1989) — Held that a quitclaim is null and void where the consideration is scandalously low and inequitable compared with the claimant's entitlement, as it is contrary to public policy.
• Olaybar vs. National Labor Relations Commission, 307 Phil. 847 (1994) — Held that a quitclaim has the effect and authority of res judicata upon the parties.
• De Andres vs. Diamond H Marine Services & Shipping Agency, Inc., 813 Phil. 746 (2017) — Held that when the consideration for the settlement is low and inequitable, a quitclaim will not bar recovery of the full measure of the worker's benefits and rights.
• F.F. Cruz & Co., Inc. vs. Galandez, G.R. No. 236496, July 8, 2019 — Held that the employer bears the burden to prove that the quitclaim is a reasonable settlement of the employee's benefits and that it was executed voluntarily with full understanding of its import.
• Leonis Navigation Co., Inc. vs. Obrero, 794 Phil. 481 (2016) — Held that in resolving compensability, only probability, not ultimate degree of certainty, is required, and that the company-designated physician's findings are not automatically binding.
• Manansala vs. Marlow Navigation Phils., Inc., 817 Phil. 84 (2017) — Held that work-relatedness requires a reasonable linkage between the disease and the work, and that a pre-existing illness may be work-related if aggravated by working conditions.
• Philippine Transmarine Carriers, Inc. vs. Bernardo, G.R. No. 220635, August 14, 2019 — Held that substantial evidence that work conditions caused or at least increased the risk of contracting the disease is required, and only reasonable proof of work connection, not direct causal relation, is needed.

• POEA Memorandum Circular No. 10 (2010), Section 20(A)(4) — Provides that illnesses not listed in Section 32 of the contract are disputably presumed as work-related. Applied to colon cancer, which is not listed under Section 32-A, shifting the burden to respondents to prove otherwise.
• POEA Memorandum Circular No. 10 (2010), Section 20(A)(3) — Requires the seafarer to submit to a post-employment medical examination by a company-designated physician within three working days upon return, and allows a third doctor if the seafarer's doctor disagrees; the third doctor's decision is final and binding. The Court considered the company-designated physician's assessment but found it incomplete.
• POEA Memorandum Circular No. 10 (2010), Section 20(B)(1) — Provides that in case of work-related death during the term of the contract, the employer shall pay the beneficiaries US$50,000.00 and an additional US$7,000.00 to each child under twenty-one, not exceeding four children. This was the basis for the death benefit award.
• POEA Memorandum Circular No. 10 (2010), Section 20(B)(4)(c) — Provides that the employer shall pay the beneficiaries US$1,000.00 for burial expenses. This was awarded to petitioners.
• POEA Memorandum Circular No. 10 (2010), Section 32-A — Lists occupational diseases and provides that for an occupational disease and the resulting disability or death to be compensable, all of the following must be satisfied: the seafarer's work must involve the risks described; the disease was contracted as a result of exposure to the described risks; the disease was contracted within a period of exposure and under such other factors necessary to contract it; and there was no notorious negligence on the part of the seafarer. The Court applied these conditions in finding compensability.
• Rules of Court, Rule 45, Section 1 — Limits petitions for review on certiorari to questions of law. The Court applied the exceptions to this rule because the Court of Appeals overlooked relevant and crucial facts.
• Civil Code, Article 2208(8) — Allows recovery of attorney's fees in actions for indemnity under workmen's compensation and employer's liability laws. The Court awarded attorney's fees equivalent to 10% of the total monetary award.

Carandang, Zalameda, and Gaerlan, JJ., concur.

• Justice Alexander Gesmundo — Dissented on the ground that there was no substantial evidence to prove that Castillon's illness was work-related. He pointed out that Castillon's cancer was already critical at the time he was employed, so it could not be ruled that his condition developed or progressed while on board the vessel; that the claim that his cancer was aggravated by his diet and living conditions was merely speculative; and that the pre-employment medical examination could not have detected an asymptomatic illness because the examination is only routinary. The majority disagreed, holding that work-relatedness requires only a reasonable link and not sole causation, that the severity and progression of the illness is not the test, and that substantial evidence showed the working conditions contributed to or aggravated the illness.