B. COMPENSATION AND BENEFITS FOR INJURY OR ILLNESS   The liabilities of the employer when the seafarer suffers work-related injury or illness during the term of his contract are as follows:   xxxx   6. In case of permanent total or partial disability of the seafarer caused by either injury or illness the seafarer shall be compensated in accordance with the schedule of benefits enumerated in Section 32 of this Contract. Computation of his benefits arising from an illness or disease shall be governed by the rates and the rules of compensation applicable at the time the illness or disease was contracted. [Emphasis supplied.]   Evident from the afore-quoted provision is that the permanent total or partial disability suffered by a seafarer during the term of his contract must be caused by work-related illness or injury. In other words, to be entitled to compensation and benefits under said provision, it is not sufficient to establish that the seafarers illness or injury has rendered him permanently or partially disabled, but it must also be shown that there is a causal connection between the seafarers illness or injury and the work for which he had been contracted for.   Accordingly, in order to hold Trans-Global and Ventnor liable for payment of his claims under Sec. 20(b), paragraph 6, of the2000 POEA Amended Standard Terms and Conditions Governing the Employment of Filipino Seafarers on Board Ocean-Going Vessels, Masangcay must prove that he is suffering from permanent total or partial disability due to a work-related illness occurring during the term of his contract. Proof that he not only acquired or contracted his illness during the term of his employment contract is clearly not enough; Masangcay must also present evidence that such infirmity was work-related, or at the very least aggravated by the conditions of the work for which he was contracted for.   In the case of Rio v. Employees Compensation Commission, this Court had the occasion to state that a claimant must submit such proof as would constitute a reasonable basis for concluding either that the conditions of employment of the claimant caused the ailment or that such working conditions had aggravated the risk of contracting that ailment. 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,