Estimating Dioxin Exposure from Indoor Woodsmoke and the Burning of Plastics

描述(由调查人员提供)：木材用于烹饪，取暖是世界上很大一部分人口的基本燃料。通常，烹饪和空间供暖是在室内效率低下的无通风炉子上进行的，这会使许多人暴露在非常高浓度的木烟中。烟雾的成分包括数百种不完全燃烧产生的化合物，其中许多是有毒的，甚至是致癌的。二恶英和呋喃是世界上一些最有毒的物质，它们与其他数百种化合物一起在木材燃烧中形成。以单位燃料质量的二恶英/呋喃计算，木材火灾排放的二恶英浓度低于工业废物处理排放的二恶英浓度。然而，对一个人在厨房里在明火上做饭时吸入的二恶英/呋喃的实际数量的估计要高得多。对一名在明火上做饭的女性的每日摄入量进行粗略估计，得出的摄入量在二恶英和呋喃的国际限量范围内。过去八年来，我们一直在危地马拉农村高地研究烹饪产生的室内木烟的影响。这项研究提供了大量关于木烟的影响以及改进炉子作为干预措施的成功的信息。在危地马拉逗留期间，我们注意到在火中添加塑料作为废物处理手段的做法，因为在这些贫穷地区没有垃圾处理。焚烧垃圾的做法在世界各地很常见，特别是在已经被室内生物质烟雾焚烧的贫困地区。塑料的添加可能会增加二恶英的浓度，造成更大的暴露在剧毒化合物中。为了更好地估计木材和塑料烟雾引起的二恶英暴露风险的数量级，我们将对二恶英的浓度进行量化。我们将首先进行一系列基于实验室的室内实验，以完善现场采样技术以及化学分析。然后，我们将测量一个典型的危地马拉乡村厨房中木头和塑料以不同比例燃烧时的二恶英浓度。使用这些数据和关于塑料燃烧的调查，以及厨房颗粒物浓度，以及从我们之前在同一地区进行的两项研究中收集的个人暴露于室内空气污染的情况，我们将估计木材烟雾中的二恶英暴露量以及塑料燃烧可能增加的浓度。这项研究将对木材和塑料燃烧产生的二恶英暴露提供更准确的估计，并可能突出暴露于一种剧毒污染物的大量人群中。 与公众健康相关：二恶英被认为是人类已知的最危险的化学物质之一。量化与室内烹饪相关的木头和塑料烟雾的暴露，可能会揭示出已经背负着严重贫困负担的人以前从未测量到的大量暴露。

DESCRIPTION (provided by investigator): Wood for cooking, and heating is an essential fuel to a large portion of world's population. Often cooking and space heating occurs on inefficient unvented stoves indoors exposing many to very high concentrations of wood smoke. The components of the smoke include hundreds of compounds created from incomplete combustion, many of which are toxic and even carcinogenic. Dioxins and furans, some of the most toxic substances in the world, are formed in wood combustion along with the other hundreds of compounds. The concentrations of dioxins emitted from a wood fire are lower than those from an industrial waste process when compared on a dioxin/furan per unit fuel mass basis. However an estimation of the actual quantity of dioxins/furans inhaled by a person in a kitchen cooking over an open fire is much higher. A rough estimation of the daily intake fraction of a woman, who cooks over an open fire yielded an intake that was in the range of international limits for dioxins and furans. We have been studying the impacts of indoor wood smoke from cooking for the past eight years in the rural highlands of Guatemala. This research has provided a wealth of information about the impacts of wood smoke and the success of an improved stove as an intervention. During the time spent in Guatemala we have noticed the practice of adding plastic to a fire as means of waste disposal as trash disposal is not available in such poor areas. The practice of burning trash is commonplace worldwide, especially in poor areas already burned with indoor biomass smoke. The addition of plastic may increase the concentrations of dioxins creating an even larger exposure to extremely toxic compounds. In order to better estimate the order of magnitude of the risk from dioxin exposure due to wood and plastic smoke we will quantify the concentrations of dioxins. We will first conduct a series of lab based chamber experiments to perfect a field sampling technique, as well as the chemical analysis. Then we will measure dioxin concentrations in a typical Guatemalan village kitchen from both wood and plastic combustion at varying ratios. Using this data and surveys on plastic burning along with kitchen particulate matter concentrations, and personal exposures to indoor air pollution collected from our two previous research studies in the same area, we will estimate dioxin exposure from wood smoke and the possibly increased concentrations from plastic burning. This study will provide a more accurate estimate of dioxin exposure from wood and plastic combustion, and possibly highlight an exposure to a large population of a extremely toxic pollutant. PUBLIC HEALTH RELEVANCE: Dioxins are considered to be one of the most dangerous chemical known to man. Quantifying exposures from wood and plastic smoke associated with indoor cooking may reveal a large previously unmeasured exposure to people already burdened with the severity of poverty.