Department of Civil and Environmental Engineering, Colorado School of Mines , Golden, Colorado 80401, United States.
Environ Sci Technol. 2013 Dec 17;47(24):14062-9. doi: 10.1021/es403094q. Epub 2013 Nov 21.
The presence of perfluoroalkyl acids (PFAAs) in biosolids destined for use in agriculture has raised concerns about their potential to enter the terrestrial food chain via bioaccumulation in edible plants. Uptake of PFAAs by greenhouse lettuce ( Lactuca sativa ) and tomato ( Lycopersicon lycopersicum ) grown in an industrially impacted biosolids-amended soil, a municipal biosolids-amended soil, and a control soil was measured. Bioaccumulation factors (BAFs) were calculated for the edible portions of both lettuce and tomato. Dry weight concentrations observed in lettuce grown in a soil amended (biosolids:soil dry weight ratio of 1:10) with PFAA industrially contaminated biosolids were up to 266 and 236 ng/g for perfluorobutanoic acid (PFBA) and perfluoropentanoic acid (PFPeA), respectively, and reached 56 and 211 ng/g for PFBA and PFPeA in tomato, respectively. BAFs for many PFAAs were well above unity, with PFBA having the highest BAF in lettuce (56.8) and PFPeA the highest in tomato (17.1). In addition, the BAFs for PFAAs in greenhouse lettuce decreased approximately 0.3 log units per CF2 group. A limited-scale field study was conducted to verify greenhouse findings. The greatest accumulation was seen for PFBA and PFPeA in both field-grown lettuce and tomato; BAFs for PFBA were highest in both crops. PFAA levels measured in lettuce and tomato grown in field soil amended with only a single application of biosolids (at an agronomic rate for nitrogen) were predominantly below the limit of quantitation (LOQ). In addition, corn ( Zea mays ) stover, corn grains, and soil were collected from several full-scale biosolids-amended farm fields. At these fields, all PFAAs were below the LOQ in the corn grains and only trace amounts of PFBA and PFPeA were detected in the corn stover. This study confirms that the bioaccumulation of PFAAs from biosolids-amended soils depends strongly on PFAA concentrations, soil properties, the type of crop, and analyte.
全氟烷基酸（PFAAs）在用于农业的生物固体中的存在引起了人们的关注，因为它们有可能通过在可食用植物中的生物积累而进入陆地食物链。本研究测量了在受工业影响的生物固体改良土壤、市政生物固体改良土壤和对照土壤中生长的温室生菜（ Lactuca sativa ）和番茄（ Lycopersicon lycopersicum ）对 PFAAs 的吸收。计算了生菜和番茄可食用部分的生物积累因子（BAF）。在添加了全氟丁酸（PFBA）和全氟戊酸（PFPeA）工业污染生物固体的土壤（生物固体：土壤干重比为 1:10）中生长的生菜中，观察到的干重浓度分别高达 266 和 236 ng/g，而在番茄中，PFBA 和 PFPeA 的浓度分别为 56 和 211 ng/g。许多 PFAAs 的 BAF 均远高于 1，其中 PFBA 在生菜中的 BAF 最高（56.8），PFPeA 在番茄中的 BAF 最高（17.1）。此外，温室生菜中 PFAAs 的 BAF 每增加一个 CF2 基团大约降低 0.3 个对数单位。进行了一项有限规模的田间研究来验证温室研究结果。在田间生长的生菜和番茄中，PFBA 和 PFPeA 的积累量最大；在这两种作物中，PFBA 的 BAF 最高。在仅用生物固体进行单次施用量（按氮的农业用量）改良的田间土壤中种植的生菜和番茄中，测量到的 PFAA 水平主要低于定量限（LOQ）。此外，还从几个大规模生物固体改良农田中收集了玉米（ Zea mays ）秸秆、玉米籽粒和土壤。在这些农田中，玉米籽粒中的所有 PFAAs 均低于 LOQ，仅在玉米秸秆中检测到痕量的 PFBA 和 PFPeA。本研究证实，生物固体改良土壤中 PFAAs 的生物积累强烈依赖于 PFAAs 浓度、土壤特性、作物类型和分析物。
