Van Den Oever R U, Roosels D, Lahaye D
Br J Ind Med. 1982 May;39(2):140-4. doi: 10.1136/oem.39.2.140.
Methyl bromide, a highly toxic and ready penetrating fumigant, is widely used against rodents, insects, mites, and a range of pathogenic organisms in soil, compost, and timber. To disinfect soil in greenhouses, methyl bromide is brought under pressure from outside by a vaporiser and blown on to ground under a polyethylene cover. The gas being three times heavier than air easily penetrates the ground. Depending on the local ventilation, a considerable amount of gas evaporates into the surrounding atmosphere, this emission being especially serious during the fumigation procedure and at the removal of the plastic cover. Previously, mechanical injection of methyl bromide on to the ground within closed areas was prohibited, since this technique exposed at least four disinfection workers at a time, who were provided with only a canister respirator, to gas concentrations of over 1000 ppm CH3Br. The present study established that fumigation with methyl bromide also carries risks for the well-protected worker inside, as well as for the one controlling the vaporiser. The concentration during application varies from 30 to 3000 ppm. Concentration in the air declines with time to 4 ppm CH3Br five days after application. Discarding the plastic sheet involves exposure to peak values as high as 200 ppm for a few seconds. On the ninth day after application, milling the soil can expose workers to up to 15 ppm; on the eleventh day no CH3Br concentration in the air could be found.
溴甲烷是一种剧毒且极易渗透的熏蒸剂，广泛用于防治土壤、堆肥和木材中的啮齿动物、昆虫、螨虫及多种致病生物。为对温室土壤进行消毒，溴甲烷由汽化器从外部施加压力，通过聚乙烯覆盖物吹到地面上。该气体比空气重三倍，很容易渗透到土壤中。根据当地通风情况，相当数量的气体会蒸发到周围大气中，这种排放尤其在熏蒸过程中和移除塑料覆盖物时最为严重。以前，禁止在封闭区域内将溴甲烷机械注入地面，因为这种技术会使至少四名仅配备滤毒罐呼吸器的消毒工人同时暴露于浓度超过1000 ppm的CH₃Br气体中。本研究证实，使用溴甲烷熏蒸对内部防护良好的工人以及操作汽化器的工人也存在风险。施用期间的浓度在30至3000 ppm之间变化。施用后五天，空气中的浓度会降至4 ppm的CH₃Br。丢弃塑料薄膜会使工人在几秒钟内暴露于高达200 ppm的峰值浓度下。施用后第九天，翻耕土壤会使工人暴露于高达15 ppm的浓度下；第十一天，空气中未检测到CH₃Br浓度。
