Further Research on PFAS Pollution in China – PFAS concentrations in the environment, PFAS policies, and their impacts
Based on the brief analysis provided in October, this Newsletter aims to further examine PFAS pollution in China in three aspects, recent academic research regarding PFAS contamination, national and provincial policies on PFAS restrictions and measurement, and the evaluation of policy implementation.
First, recent research has shown that PFAS can cause contamination to the environment, posing risk to animal and human health. For instance, one research found a higher concentration of PFAS (176 pg/m3) in Chinese samples of atmospheric PM than in neighbouring countries, with PFOA and PFOS being the dominating compounds . Regarding water and soil, a study examined the PFAS contamination to water and soil in inland areas of Shandong Province found that PFAS concentrations ranged from 36.1 to 1,236.21 ng/L and 4.23–48.72 ng/g dw (dry weight) in surface water and soil separately. Therefore, in addition to those economy developing and industrial areas, such as Yangtze River and Taihu Lake, PFAS pollution might be widespread in China. Meanwhile, PFOA concentration was found to be higher than PFOS concentration in both water and soil . Li et al. show that PFAS detected in the environment are mainly caused by industrial emissions and that they accumulate in animal and human bodies . One research conducted by the U.S. Food and Drug Administration in 2022 tested 81 samples of seafood and found that canned clams imported from China contained PFAS and that their expected exposure to PFOA would likely harm human health . In addition, a recent study published in September concluded that Chinese wildlife is exposed to PFAS . Another research found that PFAS could impact both humans and animals in terms of their nervous system, organs, immunity, and some other aspects .
Second, both national and local authorities have issued some policies and standards to limit the use of and measure PFAS in various industries and activities. For example, in the textile industry, the Ministry of Environmental Protection (replaced by the MEE in 2018) set the detection limits of PFOA in textile products and other textile products at 0.05 and 0.1 mg/kg separately, and the use of PFOS in all textile products should not exceed 1.0 µg/m², which came into effect in 2017 . The relevant measure standard is GB/T 31126-2014 Textiles―Determination of perfluorooctane sulfonates and perfluoroalkyl carboxylates . In the food industry, according to the standards GB 9685-2016 National Food Safety Standard – Standard for Uses of Additives in Food Contact Materials and Their Products, and GB 4806.10-2016 National Food Safety Standard – Food Contact Paints and Coatings, issued in 2016, PFAS substances are not included in the list of allowed substances. At the meantime, the standard GB 31604.35-2016 National Food Safety Standard – Determination of PFOS and PFOA in Food Contact Materials and Products was introduced to offer guidance on measuring the concentration of these two . Regarding the provincial policies, the Guiding Opinions on the Coordinated Promotion of High-quality Water Supply for the Yangtze River Delta Integrated Development Demonstration Zone was issued by Shanghai, Jiangsu, Zhejiang, and other relevant local authorities in October, which emphasised the importance of paying attention to new pollutants including PFOS and PFOA and developing relevant testing methods.
Third, regarding the implementation of relevant PFAS policies, Figure 1 shows the production of PFOS/PFOSF in China (perfluorooctane sulfonic acid, its salts, and perfluorooctane sulfonyl fluoride, sometimes also known as PFOS/POSF) between 2002 and 2020. As shown in the figure, the production increased dramatically after 2002 and peaked in 2006, but reduced afterwards, and especially after 2014 . According to Jia et al., the rapid growth between 2002 and 2006 was probably because the world’s largest PFOS producer, the 3M Company, shut down the relevant production line in 2002, which led to the rapid growth of PFOS production in Brazil, China, and some other Asian countries. However, due to other countries’ relevant regulations on the import of PFOS in the following years, Chinese companies produced less PFOS after 2006. For example, the EU released a regulation on restricting the sale and use of PFOS in 2006, including its presence in imported products. Furthermore, PFOS/POSF were included in the list of restricted and eliminated pollutants by the Stockholm Convention in 2009, which implied the importance of phasing out these substances on a global scale . Therefore, the Chinese authorities have released several regulations to limit the production and use of PFOS/POSF since 2014,. Based on the latest data released by the MEE this year, the annual production of PFOS/POSF in China decreased to 12 tonnes in 2021 . In addition, Zhang et al. found that China has stopped producing POSF in 2021 .
Figure 1. Annual Production of PFOS/PFOSF in China during 2002-2020. (source: Zhang et al., 2022)
In terms of PFOAs, according to the statistical yearbooks published by the MEE, the production of PFOA and its related substances increased from 1,470 to 2,204 tonnes between 2020 and 2021 , . It should be noticed that PFOA and its relevant substances were recently listed in the 2023 Inventory of Severely Restricted Toxic Chemicals. A recent study also found that between 2011 and 2021, PFOA concentration increased by 86.4% in agricultural soils of Eastern China, which is one of the biggest PFAS production and consumption areas worldwide (PFOS concentration decreased by 28.2% during the same period). There are two main reasons to explain the differences between change in PFOA and PFOS concentration. First, PFOA has higher mobility, which can be transported longer distances in the soils and are more easily detected in soil samples. Second, restrictions on the production and consumption of PFOS were enforced in China 9 years prior to those imposed on PFOA . Similarly, another study showed that between 2020 and 2022, China’s groundwater PFOS concentration greatly decreased but its PFOA concentration remained high . This is probably because restrictions on PFOA were not implemented until 2023. Moreover, as experts suggested, although China has issued relevant restrictions on PFOS and PFOA production, more efforts are required to remove PFOS and PFOA already in the environment. Meanwhile, some companies have tried to use some short-chain PFAS and novel fluorinated substances to replace PFOS and PFAS. However, one of the short-chain PFAS, PFHxS, has also been found to be toxic and unsafe, and therefore included in the List of New Pollutants for Priority Management (2023 Edition). As a result, the safety of these substitutes should be evaluated soon before they are widely used.