【Haichuan. Pioneers in the Chemical Industry】Hou Debang __ A detailed analysis of the toxicity issues associated with asphalt, based on various sources

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In the early 1950s, cases of poisoning and skin diseases were found among workers who handled and used asphalt to build roads. To determine whether asphalt is toxic or not, Hou Debang held several symposiums, inviting people from various fields to participate in the discussions, and he also wrote a paper titled \"On the Toxicity of Asphalt.\" This article examines in detail the three sources of asphalt: petroleum asphalt, coal tar asphalt, and natural asphalt, and provides a thorough analysis of their production processes, concluding with relevant opinions. The paper argues that after being rigorously refined in petroleum refineries, petroleum asphalt is unlikely to contain light cyclic hydrocarbons, and very few substances can volatilize under normal temperature and pressure; therefore, it generally has low toxicity ； Natural asphalt is extracted from the ground and undergoes natural distillation, weathering, oxidation, and various natural refining processes; it contains little volatile matter, so the possibility of it containing toxins is even lower ； The tar in coal paste is definitely toxic, especially when it has not been refined at high temperatures. Using it directly for road paving not only fails to meet highway standards but also results in the waste of a valuable material, posing a risk to workers’ health. He said that coal paste needs to be carefully refined, and valuable by-products can be produced during this process. By scientifically distinguishing bitumen from different sources in this way, the problem of bitumen pollution can be effectively addressed.