School of Public Health, University of Memphis, Memphis, TN 38152, USA.
School of Public Health, University of Memphis, Memphis, TN 38152, USA.
Sci Total Environ. 2020 Nov 15;743:140774. doi: 10.1016/j.scitotenv.2020.140774. Epub 2020 Jul 6.
Fireworks on Independence Day have been identified as a nationwide but short-term source of particulate matter in the U.S. No study has specifically examined their impacts on ambient polycyclic aromatic hydrocarbons (PAHs). Based on data between 1990 and 2019 in the Air Quality System, we identified 76 unique events that had PAH measurements on both July 4th days and control days (within 15 days before and after July 4th). We compared concentrations and diagnostic ratios of 16 priority PAHs between event and control days using Wilcoxon signed-rank tests and multivariable regressions. A local PAH monitoring campaign was conducted at eight sites in Memphis, Tennessee, to obtain a close observation of PAH changes. The national geometric mean (GM) concentrations of summed 16 PAHs (ΣPAHs) were similar between event and control days (48.1 ng/m vs. 52.8 ng/m, p = 0.98). About a quarter of events had elevated PAH concentrations compared with control days. Higher diagnostic ratios were found on event days, suggesting more contributions from fireworks sources. PAHs on July 4th were unlikely to cause acute or chronic health effects. While the local monitoring showed a 15% increase of ΣPAHs on July 4th, the difference was not significant (p = 0.62). Elevated PAH concentrations occurred at sites near fireworks sources and without major traffics, but did not occur at those in remote areas or near major interstate highways. In conclusion, this study finds that Independence Day fireworks have negligible impacts on atmospheric PAHs at the national level, and are unlikely to pose significant health risks. The firework effect is localized within a limited geographic scale, suggesting potential needs for local monitoring and control programs.
美国独立日烟花已被确定为全国范围内但短期的颗粒物来源，但尚无研究专门探讨其对环境多环芳烃（PAHs）的影响。本研究基于 1990 年至 2019 年美国空气质量系统中的数据，确定了 76 个独特事件，这些事件在 7 月 4 日及对照日（7 月 4 日前后 15 天内）均有 PAH 测量值。我们使用 Wilcoxon 符号秩检验和多变量回归比较了事件日和对照日 16 种优先 PAHs 的浓度和诊断比值。在田纳西州孟菲斯的八个地点进行了局部 PAH 监测活动，以密切观察 PAH 变化。全国 16 种 PAHs 总和（ΣPAHs）的几何平均值（GM）浓度在事件日和对照日之间相似（48.1ng/m3 与 52.8ng/m3，p=0.98）。约四分之一的事件与对照日相比，PAH 浓度升高。在事件日发现了更高的诊断比值，表明烟花源的贡献更多。7 月 4 日的 PAHs 不太可能导致急性或慢性健康影响。虽然当地监测显示 7 月 4 日 ΣPAHs 增加了 15%，但差异无统计学意义（p=0.62）。在靠近烟花源且没有主要交通的地点发现了 PAH 浓度升高，但在偏远地区或靠近主要州际公路的地点并未发现。总之，本研究发现独立日烟花对全国大气 PAHs 的影响可以忽略不计，不太可能对健康造成重大风险。烟花的影响在有限的地理范围内局部化，表明需要进行当地监测和控制计划。
