ABSTRACT

Human exposure to wildfire-derived particulate matter (PM) is linked to adverse health outcomes; however, little is known regarding the influence of biomass fuel type and burn conditions on toxicity. The aim of this study was to assess the irritant potential of extractable organic material (EOM) of biomass smoke condensates from five fuels (eucalyptus, pine, pine needle, peat, or red oak), representing various fire-prone regions of the USA, burned at two temperatures each [flaming (approximately 640°C) or (smoldering approximately 500°C)] using a locomotor assay in zebrafish (Danio rerio) larvae. It was postulated that locomotor responses, as measures of irritant effects, might be dependent upon fuel type and burn conditions and that these differences relate to combustion byproduct chemistry. To test this, locomotor activity was tracked for 60 min in 6-day-old zebrafish larvae (25–32/group) immediately after exposure to 0.4% dimethyl sulfoxide (DMSO) vehicle or EOM from the biomass smoke condensates (0.3–30 µg EOM/ml; half-log intervals). All EOM samples produced concentration-dependent irritant responses. Linear regression analysis to derive rank-order potency indicated that on a µg PM basis, flaming pine and eucalyptus were the most irritating. In contrast, on an emission-factor basis, which normalizes responses to the amount of PM produced/kg of fuel burned, smoldering smoke condensates induced greater irritant responses (>100-fold) than flaming smoke condensates, with smoldering pine being the most potent. Importantly, irritant responses significantly correlated with polycyclic aromatic hydrocarbon (PAH) content, but not with organic carbon or methoxyphenols. Data indicate that fuel type and burn condition influence the quantity and chemical composition of PM as well as toxicity.

 抽象的

人类接触野火产生的颗粒物 (PM) 与不良健康结果有关；然而，人们对生物质燃料类型和燃烧条件对毒性的影响知之甚少。本研究的目的是评估来自五种燃料（桉树、松树、松针、泥炭或红橡木）的生物质烟雾凝结物的可提取有机物质（EOM）的潜在刺激性，这些燃料代表了美国的各个易发生火灾的地区，使用斑马鱼 ( Danio rerio ) 幼虫的运动测定，在两种温度下燃烧（燃烧（约 640°C）或（闷烧约 500°C））。据推测，运动反应作为刺激效应的衡量标准，可能取决于燃料类型和燃烧条件，并且这些差异与燃烧副产物的化学成分有关。为了测试这一点，在暴露于 0.4% 二甲基亚砜 (DMSO) 载体或生物质烟雾冷凝物中的 EOM（0.3-30 µg）后，立即对 6 日龄斑马鱼幼虫（25-32 只/组）的运动活动进行了 60 分钟的跟踪。 EOM/ml；半对数间隔）。所有 EOM 样品均产生浓度依赖性刺激反应。线性回归分析得出的排序效力表明，以 µg PM 为基础，火松和桉树的刺激性最强。相比之下，在排放因子基础上，将反应标准化为每公斤燃烧燃料产生的 PM 量，阴燃烟雾凝结物比燃烧烟雾凝结物引起更大的刺激反应（>100 倍），其中阴燃松树的刺激性最强。重要的是，刺激反应与多环芳烃（PAH）含量显着相关，但与有机碳或甲氧基酚无关。 数据表明，燃料类型和燃烧条件影响 PM 的数量和化学成分以及毒性。