In the small city of St. John’s, NL (2020 population ~114,000), 100% of the soils of the pre-1926 properties exceeded the Canadian soil Pb standard, 140 mg/kg. The Pb was traced to high-Pb coal ash used for heating and disposed on the soils outside. Analytical instruments became available in the late 1960s and 1970s and were first used for blood Pb and clinical studies and repurposed for measuring environmental Pb. The environmental research part of this study compared four common soil Pb analysis methods on the same set (N = 96) of St. John’s soil samples. The methods: The US EPA method 3050B, portable X-ray fluorescence spectrometry (pXRF), The Chaney–Mielke leachate extraction (1 M nitric acid), and the relative bioaccessibility leaching procedure (US EPA method 1340). Correlation is not the same as agreement. There is strong agreement (Berry–Mielke’s Universal R) among the four soil Pb analytical methods. Accordingly, precaution is normally advisable to protect children from the high-Pb garden soils and play areas. A public health reality check by Health Canada surveillance of St. John’s children (N = 257) noted remarkably low blood Pb. The low blood Pb of St. John’s’ children is contrary to the soil Pb results. Known urban processes causing the rise of environmental Pb and children’s Pb exposure includes particle size, aerosol emission by traffic congestion, and quantities of leaded petrol during the 20th century. Smaller cities had minor traffic congestion and limited combustion particles from leaded petrol. From the perspective of the 20th century era of urban Pb pollution, St. John’s, NL, children have blood Pb characteristics of a small city.

中文翻译：

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加拿大纽芬兰省圣约翰小城土壤中铅的四种分析方法协议

在荷兰的小城市圣约翰（2020 年人口约 114,000），1926 年之前特性的土壤 100% 超过了加拿大土壤铅标准，140 毫克/公斤。铅被追踪到用于加热和处理在外面土壤上的高铅煤灰。分析仪器在 1960 年代末和 1970 年代问世，最初用于血液铅和临床研究，并重新用于测量环境铅。本研究的环境研究部分在同一组 (N = 96) 的圣约翰土壤样本上比较了四种常见的土壤 Pb 分析方法。方法：US EPA 方法 3050B、便携式 X 射线荧光光谱法 (pXRF)、Chaney-Mielke 浸出液提取（1 M 硝酸）和相对生物可接近性浸出程序（US EPA 方法 1340）。相关性不等于一致。四种土壤铅分析方法之间存在很强的一致性（Berry-Mielke 的 Universal R）。因此，通常建议采取预防措施以保护儿童免受高铅花园土壤和游乐区的伤害。加拿大卫生部对圣约翰儿童 (N = 257) 进行的一项公共卫生现实调查发现，血铅含量非常低。St. John's 孩子的低血铅与土壤铅结果相反。导致环境铅和儿童铅暴露增加的已知城市过程包括颗粒大小、交通拥堵造成的气溶胶排放以及 20 世纪含铅汽油的数量。较小的城市有轻微的交通拥堵和含铅汽油的有限燃烧颗粒。从20世纪城市铅污染时代来看，荷兰圣约翰市的儿童血铅具有小城市的特征。