Dataset of BPA concentration levels in food from the second French total diet study

<strong>Information about the BPA data set</strong> <em>1. Description of the total diet study 2 (TDS2) and the BPA study</em> The French TDS2 consisted in collecting food products representative of the French population's consumption. This kind of study has been recommended by the World Health Organization (WHO) and the European Food Safety Authority (EFSA) and are implemented with standardized methods. The collected foods were prepared “as consumed” to take account of the population’s common practices, they were combined as composite/pooled samples and were analyzed for chemicals of public health interest. The aims of the TDS2 were to assess the population's exposure to the analyzed substances and the risk for the substances for which reference values exist. To achieve these objectives nearly 20,000 food products were purchased in about 30 cities throughout France (metropolitan territory) and prepared to constitute 1,319 samples corresponding to 212 food items (Sirot <em>et al</em>, 2009). Each sample was composed of 15 sub-samples of the same food and mass, considering different brands and consumer food preferences. All samples, except a few, were collected twice during the TDS to reflect the potential seasonal variability in composition or contamination. Some foods were also purchased in different regions of France because of the potential regional differences in contamination. Analysis of BPA contamination levels in food was not initially planned in the TDS2, and was conducted in a second wave of analyses. The laboratory (LABERCA) in charge of analysis verified that sample containers did not contain BPA. Some TDS samples had not a sufficient weight to be analyzed so only 207 food items were considered. <em>2. Description of the data set</em> The dataset presents the BPA contamination levels at the food item level, i.e. seasonal sample values were averaged at the regional level and then regional sample values were averaged to represent the national level. The original regional dataset is available in French at the following URL https://www.data.gouv.fr/fr/datasets/r/4b911e97-368b-4b0e-8891-cecd81aa39bb. The analytical methods and limits (limit of detection and quantification) are described in (Bemrah <em>et al</em> 2014). 2.1. Pre-processing of concentration data Left censored data (concentration value below the analytical limits) were managed under 3 hypotheses: The lowerbound (LB) hypothesis: Concentrations below the LOD (undetected substances) were replaced by 0, and concentrations below the LOQ but above the LOD (known as "traces") were replaced by the LOD value; The middlebound (MB) hypothesis: Concentrations below the LOD were replaced by ½ LOD, and concentrations below the LOQ but above the LOD were replaced by ½ (LOD+LOQ) ; Upperbound (UB) hypothesis: Concentrations below the LOD were replaced by the LOD value, and concentrations below the LOQ but above the LOD were replaced by the LOQ. 2.2. Thesaurus The variables of the dataset and their definitions were presented in the list below: family: name of the chemical group of the substance; subst: abbreviated name of the substance; subst_cn: complete name of the substance; unit: unit of the mean concentration value of the substance; mean_CONTA_LB: mean of the concentration values of sub-samples of the analyzed food calculated under the lower bound hypothesis; mean_CONTA_MB: mean of the concentration values of sub-samples of the analyzed food calculated under the middle bound hypothesis; mean_CONTA_UB: mean of the concentration values of sub-samples of the analyzed food calculated under the upper bound hypothesis; Food_code: identification number of the analyzed food; Food_group: food category of the analyzed food; Type_foods: analyzed food.<strong>关于BPA数据集的说明</strong> <em>1. 总膳食研究2（Total Diet Study 2，TDS2）与BPA研究概况</em> 法国总膳食研究2（TDS2）旨在采集能够代表法国居民消费结构的食品。该类研究已获世界卫生组织（World Health Organization，WHO）与欧洲食品安全局（European Food Safety Authority，EFSA）推荐，并采用标准化方法实施。采集的食品均以即食状态制备，以贴合居民日常食用习惯，随后被整合为复合/混合样本，并针对具有公共卫生意义的化学物质开展检测分析。 本研究的核心目标为评估人群对所检测物质的暴露水平，以及针对已制定参考值的物质开展风险评估。为达成上述目标，研究团队在法国本土约30座城市采购了近2万件食品，经制备后形成1319份样本，对应212种食品品类（Sirot et al, 2009）。每份样本由15份同品类、同质量的子样本组成，涵盖不同品牌与消费者饮食偏好。除少数样本外，TDS2均采集了两批次样本，以反映成分或污染水平潜在的季节性差异。部分食品因污染可能存在区域差异，故而在法国不同区域进行采购。 原本TDS2并未计划检测双酚A（Bisphenol A，BPA）的污染水平，相关检测在第二轮分析中开展。负责本次检测的实验室（LABERCA）已验证样本容器不含双酚A。由于部分TDS样本质量不足，无法开展检测，最终仅纳入207种食品品类。 <em>2. 数据集概况</em> 本数据集提供食品品类层面的双酚A污染水平数据，具体处理方式为：先将季节性样本值按区域层面取平均，再将区域样本值平均以得到全国层面的代表值。原始区域数据集的法语版可通过以下链接获取：https://www.data.gouv.fr/fr/datasets/r/4b911e97-368b-4b0e-8891-cecd81aa39bb。分析方法与限值（检测限Limit of Detection, LOD与定量限Limit of Quantification, LOQ）详见（Bemrah et al 2014）。 2.1 浓度数据预处理 左截尾数据（浓度值低于分析限值）基于三种假设进行处理： - 下界（LB）假设：将低于检测限（LOD）的浓度（未检出物质）替换为0，将低于定量限（LOQ）但高于检测限的浓度（即所谓痕量）替换为LOD值； - 中界（MB）假设：将低于检测限的浓度替换为½ LOD，将低于定量限但高于检测限的浓度替换为½(LOD+LOQ)； - 上界（UB）假设：将低于检测限的浓度替换为LOD值，将低于定量限但高于检测限的浓度替换为LOQ值。 2.2 术语表 数据集变量及其定义如下： - family：物质所属化学类群名称； - subst：物质的缩写名称； - subst_cn：物质的完整名称； - unit：物质平均浓度值的单位； - mean_CONTA_LB：基于下界假设计算得到的分析食品子样本浓度平均值； - mean_CONTA_MB：基于中界假设计算得到的分析食品子样本浓度平均值； - mean_CONTA_UB：基于上界假设计算得到的分析食品子样本浓度平均值； - Food_code：分析食品的标识编号； - Food_group：分析食品的食品类别； - Type_foods：待分析食品。