This is a petition for review on certiorari of the Decision^[1] of the Court of Appeals dated May 24, 2006 in CA-G.R. SP No. 88691 (the assailed Decision) and the Resolution^[2] dated August 7, 2006 issued by the same court in said case.

The facts, as summarized by the Court of Appeals, are as follows:

[Petitioner Alexander B.] Gatus worked at the Central Azucarera de Tarlac beginning on January 1, 1972.  He was a covered member of the SSS (SS No. 02-0055015-6).  He optionally retired from Central Azucarera de Tarlac upon reaching 30 years of service on January 31, 2002, at the age of 62 years.  By the time of his retirement, he held the position of Tender assigned at the Distillery Cooling Tower.

In the course of his employment in Central Azucarera de Tarlac, he was certified fit to work on October 21, 1975 and was accordingly promoted to a year-round regular employment.

He suffered chest pains and was confined at the Central Luzon Doctor's Hospital in Tarlac City on August 12, 1995.  Upon discharge on August 17, 1995, he was diagnosed to be suffering from Coronary Artery Disease (CAD): Triple Vessel and Unstable Angina.  His medical records showed him to be hypertensive for 10 years and a smoker.

On account of his CAD, he was given by the SSS the following EC/SSS Permanent Partial Disability (PPD) benefits: (a) 8 monthly pensions effective September 1, 1994 and (b) 4 monthly pensions effective January 3, 1997.  He became an SSS retirement pensioner on February 1, 2002.

Sometime in 2003, an SSS audit revealed the need to recover the EC benefits already paid to him on the ground that his CAD, being attributed to his chronic smoking, was not work-related.  He was notified thereof through a letter dated July 31, 2003.

Convinced that he was entitled to the benefits, he assailed the decision but the SSS maintained its position.  The SSS also denied his motion for reconsideration.

He elevated the matter to the ECC, which denied his appeal on December 10, 2004, essentially ruling that although his CAD was a cardiovascular disease listed as an occupational disease under Annex A of the Implementing Rules on Employees' Compensation, nothing on record established the presence of the qualifying circumstances for responsibility; that it was incumbent upon him to prove that the nature of his previous employment and the conditions prevailing therein had increased the risk of contracting his CAD; and that he had failed to prove this requisite.  The ECC concluded:

As explained medically, the development of IHD or otherwise termed as Coronary Artery Disease (CAD) is caused by atherosclerosis, the hardening of the inner lining of arteries.  One of the risk factors considered by medical science for the development of atherosclerosis is smoking.  Appellant had been documented to be a chronic smoker and such factor which is not in any way related to any form of employment increased his risk of contracting heart disease.

Hence, this recourse, wherein he contends that he had contracted the disease due to the presence of harmful fuel smoke emission of methane gas from a nearby biological waste digester and a railway terminal where diesel-fed locomotive engines had "spew(ed) black smoke;" and that he had been exposed for 30 years to various smoke emissions that had contained carbon monoxide, carbon dioxide, sulfur, oxide of nitrogen and unburned carbon.^[3]  (Emphases added.)

In the assailed Decision, the Court of Appeals held that petitioner is not entitled to compensation benefits under Presidential Decree No. 626, as amended, affirming the Decision of the Employees' Compensation Commission (ECC), which was likewise a confirmation of the audit conducted by the Social Security System (SSS).

Thus, this petition wherein, even without assistance of counsel, petitioner comes to this Court contending that "the appellate court's decision is flawed [and] if not reversed will result in irreparable damage to the interest of the petitioner."^[4]

Petitioner lists the following as errors in the questioned Decision:

1. The appellate court's decision is against existing jurisprudence on increased risk theory of rebook condition and progression and deterioration of illness that supervened during employment and persisted after optional retirement.
   
   
2. Violation of due process.^[5]
   

The Court of Appeals agreed with the ECC's findings that based on his medical records, petitioner has been hypertensive for ten (10) years and smokes 20 packs of cigarettes a year.^[6]  His medical condition was explained in the following manner by the ECC:

Ischemic Heart Disease (IHD) is the generic designation for a group of closely related syndromes resulting from ischemia - an imbalance between the supply and demand of the heart for oxygenated blood. Because coronary artery narrowing or obstruction owing to atherosclerosis underlies MI, it is often termed coronary artery disease (CAD). Atherosclerosis which is primarily due to smoking, diet, hypertension and diabetes is the main culprit in the development of CAD. (Pathologic Basis of Disease by Robbins, 5^th edition.)^[7] (Emphasis supplied.)

Petitioner claims that he was in good health when he first entered the Central Azucarera de Tarlac as a factory worker at the Alcohol Distillery Plant in 1972.^[8]  He alleges that in the course of his employment he suffered "essential hypertension" starting 1995, when he experienced chest pains and was confined at the Central Luzon Doctor's Hospital in Tarlac City; that he was diagnosed as having "Coronary Artery Disease (CAD) [Triple] Vessel and Angina Pectoris" and hypertension; that he was initially granted disability benefits by the SSS but his request for additional benefits was denied; and that the ECC denied his appeal due to allegations of smoking. He asserts that he has cited "technical, scientific and medical authorities to bolster his claim" including the exposure he experienced for thirty (30) years from the alcohol distillery to "hydrocarbons and [locomotives]," carbon monoxide, carbon dioxide, sulfur, phosphorous, nitrogen oxides and soot (particulate matter). ^[9]

Petitioner uses various references, including encyclopedia and medical books, to discuss the general effects of pollution, mostly caused by the burning of fossil fuels, to people with cardiovascular diseases; and the aggravation of coronary artery diseases brought about by exposure to carbon monoxide.^[10]  Petitioner claims that "air pollution (carbon monoxide and lead from gasoline) contributed to the development of essential hypertension and its complications: [c]oronary artery disease, hypertensive cardiovascular disease and stroke."^[11]

Petitioner insists that the allegation of cigarette smoking was not proven and that the ECC did not present a document signed by competent medical authority to back such claim.  Petitioner claims that there is no showing that the ECC records were elevated to the Court of Appeals, and that the latter had completely ignored his evidence.

In its Comment^[12] dated December 11, 2006, respondent SSS alleges that the Decision of the Court of Appeals affirming the Decision of the ECC was in accordance with law and existing jurisprudence.  Respondent SSS further alleges that as viewed from the records of the case, the petitioner failed to show proof by mere substantial evidence that the development of his disease was work-related;^[13] that petitioner's heart ailment had no causal relation with his employment; and that "[as] viewed from by his lifestyle, he was a chain smoker, a habit [which had] contributed to the development of his heart ailment."^[14]

Respondent further alleges that medical findings have revealed that nicotine in cigarette smoke damages the blood vessels of the heart, making them susceptible to the hardening of the inner lining of the arteries.  As to petitioner's contention that there were harmful fuel and smoke emissions due to the presence of methane gas from a nearby biological waste as well as a railway terminal where diesel-fed locomotive engines spewed black smoke, respondent counters that these were mere allegations that were not backed by scientific and factual evidence and that petitioner had failed to show which harmful emissions or substances were present in his working environment and how much exposure thereto had contributed to the development of his illness.  Respondent points out that petitioner's "bare allegations do not constitute such evidence that a reasonable mind might accept as adequate to support the conclusion that there is a causal relationship between his working conditions" and his sickness and that "the law is clear that award of compensation cannot rest on speculations or presumptions."^[15]

The sole issue to be determined is whether the Court of Appeals committed grave abuse of discretion in affirming the finding of the ECC that petitioner's ailment is not compensable under Presidential Decree No. 626, as amended.

The grounds for compensability are set forth in Section 1, Rule III of the Amended Rules on Employees' Compensation (the "Amended Rules"), the pertinent portion of which states:

RULE III
Compensability
Sec. 1.Grounds -- x x x

(b) For the sickness and the resulting disability or death to be compensable, the sickness must be the result of an occupational disease listed under Annex "A"of these Rules with the conditions set therein satisfied; otherwise, proof must be shown that the risk of contracting the disease is increased by the working conditions.

Further, under Annex "A" of the Amended Rules,

For an occupational disease and the resulting disability or death to be compensable, all of the following conditions must be satisfied:

1. The employee's work must involve the risks described herein;
   
2. The disease was contracted as a result of the employee's exposure to the described risks;
   
3. The disease was contracted within a period of exposure and under such other factors necessary to contract it;
   
4. There was no notorious negligence on the part of the employee.

Cardiovascular diseases are considered as occupational when contracted under any of the following conditions:

(a) If the heart disease was known to have been present during employment there must be proof that an acute exacerbation clearly precipitated by the unusual strain by reason of the nature of his work.

(b) The strain of work that brings about an acute attack must be of sufficient severity and must be followed within twenty-four (24) hours by the clinical signs of a cardiac insult to constitute causal relationship.

(c) If a person who was apparently asymptomatic before subjecting himself to strain at work showed signs and symptoms of cardiac injury during the performance of his work and such symptoms and signs persisted, it is reasonable to claim a causal relationship.^[16]

The burden of proof is thus on petitioner to show that any of the above conditions have been met in his case.  The required proof is further discussed in Ortega v. Social Security Commission^[17]:

The requisite quantum of proof in cases filed before administrative or quasi-judicial bodies is neither proof beyond reasonable doubt nor preponderance of evidence. In this type of cases, a fact may be deemed established if it is supported by substantial evidence, or that amount of relevant evidence which a reasonable mind might accept as adequate to justify a conclusion. In this case, substantial evidence abounds.^[18]

As found by the Court of Appeals, petitioner failed to submit substantial evidence that might have shown that he was entitled to the benefits he had applied for.  We thus affirm in toto the findings and conclusions of the Court of Appeals in the questioned Decision and quote with approval the following pronouncements of the appellate court:

The degree of proof required under P.D. 626 is merely substantial evidence, which means such relevant evidence as a reasonable mind might accept as adequate to support a conclusion.  Accordingly, the claimant must show, at least by substantial evidence, that the development of the disease was brought about largely by the conditions present in the nature of the job.  What the law requires is a reasonable work connection, not a direct causal relation.

Gatus was diagnosed to have suffered from CAD; Triple Vessel and Unstable Angina, diseases or conditions falling under the category of Cardiovascular Diseases which are not considered occupational diseases under the Amended Rules on Employees Compensation.  His disease not being listed as an occupational disease, he was expected to show that the illness or the fatal disease was caused by his employment and the risk of contracting the disease was increased or aggravated by the working conditions.  His proof would constitute a reasonable basis for arriving at a conclusion that the conditions of his employment had caused the disease or that such working conditions had aggravated the risk of contracting the illness or the fatal disease.

Under ECC Resolution No. 432 dated July 20, 1977, cardiovascular disease is deemed compensable under any of the following conditions, viz:

(a) If the heart disease was known to have been present during employment, there must be proof that an acute exacerbation was clearly precipitated by the unusual strain by reasons of the nature of his work.

(b) The strain of work that brings about an acute attack must be of sufficient severity and must be followed within 28 hours of the clinical signs of cardiac insult to constitute causal relationship.

x x x x

Gatus did not discharge the burden of proof imposed under the Labor Code to show that his ailment was work-related.  While he might have been exposed to various smoke emissions at work for 30 years, he did not submit satisfactory evidence proving that the exposure had contributed to the development of his disease or had increased the risk of contracting the illness.  Neither did he show that the disease had progressed due to conditions in his job as a factory worker.  In fact, he did not present any physician's report in order to substantiate his allegation that the working conditions had increased the risk of acquiring the cardiovascular disease.

Verily, his mere contention of exposure to various smoke emissions in the working environment for a period of time does not ipso facto make the resulting disability compensable.  Awards of compensation cannot rest on speculations or presumptions, for the claimant must prove a positive proposition.  As pronounced in Sante v. Employees' Compensation Commission:

x x x What kind and quantum of evidence would constitute an adequate basis for a reasonable man (not necessarily a medical scientist) to reach one or the other conclusion, can obviously be determined only on a case-to-case basis.  That evidence must, however, be real and substantial, and not merely apparent; for the duty to prove work-causation or work-aggravation imposed by existing law is real... not merely apparent...

Moreover, he failed to show the presence of any of the conditions imposed for cardio-vascular diseases by Sec. 18. Hence, the affirmance of the SSS decision was properly made.

The petitioner's plight might call for sympathy, particularly in the light of his 30 years of service to the company, but his petition cannot be granted on that basis alone.  The policy of extending the applicability of P.D. 626 as many qualified employees as possible should be balanced by the equally vital interest of denying undeserving claims for compensation.

In fine, Gatus was not qualified for the disability benefits under the employees compensation law.

WHEREFORE, the Decision of the Employees Compensation Commission is AFFIRMED.^[19]

Petitioner filed a Motion for Reconsideration but this was denied by the Court of Appeals in its Resolution dated August 7, 2006, which states:

Finding nothing cogent and persuasive in the petitioner's Motion for Reconsideration dated June 20, 2006, we DENY the motion.

We point out that our decision of May 24, 2006 has fully explained the bases for the ruling we have made, including the matters being discussed by the petitioner in his Motion for Reconsideration.  We consider it repetitious and redundant to discuss them herein again.^[20]

The questioned Decision deemed as established fact that petitioner is a cigarette smoker; but petitioner vehemently denies this, saying there is no competent evidence to prove he had that habit.  What petitioner would like this Court to do is to pass upon a question of fact, which the ECC, the SSS, and the Court of Appeals have used to deny his claim for compensation.  This is not allowed under Section 1 of Rule 45, which states that "[t]he petition shall raise only questions of law which must be distinctly set forth."^[21]  Hence, questions of fact may not be taken up in a petition for review on certiorari such as this case now before us.  As we have held previously:

A question of fact exists when the doubt centers on the truth or falsity of the alleged facts while a question of law exists if the doubt centers on what the law is on a certain set of facts. There is a question of fact if the issue requires a review of the evidence presented or requires the re-evaluation of the credibility of witnesses. However, if the issue raised is capable of being resolved without need of reviewing the probative value of the evidence, the question is one of law.^[22]

This was emphasized in La Union Cement Workers Union v. National Labor Relations Commission,^[23] thus:

As an overture, clear and unmistakable is the rule that the Supreme Court is not a trier of facts. Just as well entrenched is the doctrine that pure issues of fact may not be the proper subject of appeal by certiorari under Rule 45 of the Revised Rules of Court as this mode of appeal is generally confined to questions of law. We therefore take this opportunity again to reiterate that only questions of law, not questions of fact, may be raised before the Supreme Court in a petition for review under Rule 45 of the Rules of Court. This Court cannot be tasked to go over the proofs presented by the petitioners in the lower courts and analyze, assess and weigh them to ascertain if the court a quo and the appellate court were correct in their appreciation of the evidence.^[24]

The matter of petitioner's cigarette smoking, established by two competent government agencies and the appellate court, is thus a matter that cannot be questioned before us via petition for review.

There is no doubt that petitioner deserves sympathy because even the benefits already given to him were questioned after the SSS found that he was a chronic cigarette smoker.  For humanitarian reasons, as he pursued his claim all the way to the Court as an indigent litigant, and due to his advancing age, we would like to clarify that what had already been given him should no longer be taken away from him. But he is not entitled to further compensation for his condition.

We have once more put great weight to the factual findings of administrative agencies and quasi-judicial bodies, namely the SSS and the ECC, as they have acquired expertise in all matters relating to employee compensation and disability benefits.  As we have held in Ortega v. Social Security Commission^[25]:

It is settled that the Court is not a trier of facts and accords great weight to the factual findings of lower courts or agencies whose function is to resolve factual matters. It is not for the Court to weigh evidence all over again. Moreover, findings of fact of administrative agencies and quasi-judicial bodies, which have acquired expertise because their jurisdiction is confined to specific matters, are generally accorded not only respect but finality when affirmed by the Court of Appeals.^[26]

WHEREFORE, premises considered, the petition is hereby DENIED.

SO ORDERED.

Corona, C.J., (Chairperson), Velasco, Jr., Del Castillo, and Perez, JJ., concur.

---

^[1] Rollo, pp. 15-20; penned by Associate Justice Lucas P. Bersamin (now a member of this Court) with Associate Justices Renato C. Dacudao and Mariflor Punzalan Castillo, concurring.

^[2] Id. at 28.

^[3] Id. at 16-17.

^[4]Id. at 2.

^[5]Id.

^[6]CA rollo, p. 17.

^[7]Id. at 18.

^[8] Rollo, p. 2.

^[9] Id. at 3.

^[10] Id. at 3-5.

^[11] Id. at 5.

^[12] Id. at 54-59.

^[13] Id. at 55.

^[14] Id. at 56.

^[15] Id. at 57.

^[16] No. 18, Annex "A," Amended Rules on Employees' Compensation.

^[17] G.R. No. 176150, June 25, 2008, 555 SCRA 353.

^[18] Id. at 364.

^[19] Rollo, pp. 18-20.

^[20] Id. at 28.

^[21] The Petition was filed on August 31, 2006, prior to the amendment of Rule 45 by A.M. No. 07-7-12-SC on December 27, 2007.  The text of Rule 45, Section 1 then read:

A party desiring to appeal by certiorari from a judgment or final order or resolution of the Court of Appeals, the Sandiganbayan, the Regional Trial Court or other courts whenever authorized by law, may file with the Supreme Court a verified petition for review on certiorari. The petition shall raise only questions of law which must be distinctly set forth.

^[22] Development Bank of the Philippines v. Traders Royal Bank, G.R. No. 171982, August 18, 2010.

^[23] G.R. No. 174621, January 30, 2009, 577 SCRA 456.

^[24] Id. at 462.

^[25] Supra note 17.

^[26] Id. at 363-364.