Characterisation of plastic microbeads in facial scrubs and their estimated emissions in Mainland China

Plastic microbeads are often added to personal care and cosmetic products (PCCPs) as an abrasive agent in exfoliants. These beads have been reported to contaminate the aquatic environment and are sufficiently small to be readily ingested by aquatic organisms. Plastic microbeads can be directly released into the aquatic environment with domestic sewage if no sewage treatment is provided, and they can also escape from wastewater treatment plants (WWTPs) because of incomplete removal. However, the emissions of microbeads from these two sources have never been estimated for China, and no regulation has been imposed on the use of plastic microbeads in PCCPs. Therefore, in this study, we aimed to estimate the annual microbead emissions in Mainland China from both direct emissions and WWTP emissions. Nine facial scrubs were purchased, and the microbeads in the scrubs were extracted and enumerated. The microbead density in those products ranged from 5219 to 50,391 particles/g, with an average of 20,860 particles/g. Direct emissions arising from the use of facial scrubs were estimated using this average density number, population data, facial scrub usage rate, sewage treatment rate, and a few conservative assumptions. WWTP emissions were calculated by multiplying the annual treated sewage volume and estimated microbead density in sewage. We estimated that, on average, 209.7 trillion microbeads (306.9 tonnes) are emitted into the aquatic environment in Mainland China every year. More than 80% of the emissions originate from incomplete removal in WWTPs, and the remaining 20% is derived from direct emissions. Although the weight of the emitted microbeads only accounts for approximately 0.03% of the plastic waste input into the ocean from China, the number of microbeads emitted far exceeds the previous estimate of plastic debris (>330 μm) on the world’s sea surface. Immediate actions are required to prevent plastic microbeads from entering the aquatic environment.

Pui Kwan Cheung, Lincoln Fok, Water Research, Volume 122, 1 October 2017, Pages 53–61

The article

Microplastics in sediments of the Changjiang Estuary, China

Microplastics are plastics that measure less than 5 mm in diameter. They enter the marine environment as primary sources directly from industrial uses, as well as secondary sources resulting from the degradation of large plastic debris. To improve the knowledge of microplastic pollution in China, we investigated samples from 53 estuarine sediment locations collected with a box corer within the Changjiang Estuary. Microplastics (<5 mm) were extracted from sediments by density separation, after which they were observed under a microscope and categorized according to shape, color and size. Identification was carried out using Micro-Fourier-Transform Infrared Spectroscopy (μ-FT-IR).

The abundance of microplastics in the Changjiang Estuary was mapped. The mean concentration was 121 ± 9 items per kg of dry weight, varying from 20 to 340 items per kg of dry weight. It was found that the concentration of microplastics was the highest on the southeast coast of Shanghai. The distribution pattern of microplastics may be affected by the Changjiang diluted water in summer. All of the microplastics collected were categorized according to shape, color and size. Among which fiber (93%), transparent (42%) and small microplastics (<1 mm) (58%) were the most abundant types. No clear correlation between microplastics and the finer sediment fraction was found. Rayon, polyester, and acrylic were the most abundant types of microplastics identified, indicating that the main source of microplastics in the Changjiang Estuary was from washing clothes (the primary source). It is possible to compare microplastic abundance in this study with the results of other related studies using the same quantification method. The identification of microplastics raises the awareness of microplastic pollution from drainage systems. The prevalence of microplastic pollution calls for monitoring microplastics at a national scale on a regular basis.

Guyu Peng, Bangshang Zhu, Dongqi Yang, Lei Su, Huahong Shi, Daoji Li, Environmental Pollution, Volume 225, June 2017, Pages 283–290

The article

Occurrence and Characteristics of Microplastic Pollution in Xiangxi Bay of Three Gorges Reservoir, China

Microplastic pollution in inland waters is receiving growing attentions. Reservoirs are suspected to be particularly vulnerable to microplastic pollution. However, very limited information is currently available on pollution characteristics of microplastics in reservoir ecosystems. This work studied the distribution and characteristics of microplastics in the backwater area of Xiangxi River, a typical tributary of the Three Gorges Reservoir. Microplastics were detected in both surface water and sediment with concentrations ranging from 0.55 × 105 to 342 × 105 items km–2 and 80 to 864 items m–2, respectively. Polyethylene, polypropylene, and polystyrene were identified in surface water, whereas polyethylene, polypropylene, and polyethylene terephthalate, and pigments were observed in sediment. In addition, microplastics were also detected in the digestion tracts of 25.7% of fish samples, and polyethylene and nylon were identified. Redundancy analysis indicates a weak correlation between microplastics and water quality variables but a negative correlation with water level of the reservoir and Secchi depth. Results from this study confirm the presence of high abundance microplastics in reservoir impacted tributaries, and suggest that water level regulated hydrodynamic condition and input of nonpoint sources are important regulators for microplastic accumulation and distribution in the backwater area of reservoir tributaries.

Kai Zhang, Xiong Xiong, Hongjuan Hu and al., Environ. Sci. Technol., 2017, 51 (7), pp 3794–3801

The article

Distribution, potential sources and ecological risks of two persistent organic pollutants in the intertidal sediment at the Shuangtaizi Estuary, Bohai Sea of China

Spatial distribution, source apportionment, and potential ecological risks of sixteen polycyclic aromatic hydrocarbons (PAHs) and seven endocrine disrupting compounds (EDCs) in the intertidal sediment at the Shuangtaizi Estuary, Bohai Sea of China were analyzed. Results showed that the total PAH concentrations ranged from 28.79 ng g− 1 dw to 281.97 ng g− 1 dw (mean: 115.92 ng g− 1 dw) and the total EDC concentrations from 0.52 ng g− 1 dw to 126.73 ng g− 1 dw (mean: 37.49 ng g− 1 dw). The distribution pattern for the PAHs was generally different from that of the EDCs possibly due to their distinct sources and n-octanol-/water partition coefficients (KOW). Qualitative and quantitative analytical results showed that PAH sources were mainly from a mixture of pyrogenic and petrogenic contributions. The higher levels at the southeast of Geligang indicated that the EDC pollutants may have mainly originated from the plastic industry and other chemical plants located along the Liao River. Ecological risk assessment revealed that PAHs exhibited low ecotoxicological effects, whereas EDCs, especially 4-tert-octylphenol and bisphenol A, had high ecological hazard to the estuarine biota.

Xiutang Yuan, Xiaolong Yang, Anguo Zhang, Xindong Ma, Hui Gao, Guangshui Na, Humin Zong, Guize Liu, Yongguang Sun, Marine Pollution Bulletin, Volume 114, Issue 1, 15 January 2017, Pages 419–427

The article

China : State research project dedicated to marine microplastics

A national key research project on microplastics was recently launched in Shanghai to assess their impact on the ecological environment, especially in the ocean.

Led by East China Normal University, the study will be conducted by several college laboratories and research institutions in a time span from 2016 to late 2020 and aims to detect marine microplastics, establish research standards and monitoring procedures and develop ways to control their risks on the ecosystem.

Microplastics, which are small particles of plastic debris found in cosmetics and cleaning products like toothpastes, are too small to be captured through existing wastewater treatment processes and are washed straight into the oceans. (…) (China.org.cn, February 21, 2017)

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Ingestion of microplastics by natural zooplankton groups in the northern South China Sea

The ingestion of microplastics by five natural zooplankton groups in the northern South China Sea was studied for the first time and two types of sampling nets (505 μm and 160 μm in mesh size) were compared. The microplastics were detected in zooplankton sampled from 16 stations, with the fibrous microplastics accounting for the largest proportion (70%). The main component of the found microplastics was polyester. The average length of the microplastics was 125 μm and 167 μm for Nets I and II, respectively. The encounter rates of microplastics/zooplankton increased with trophic levels. The average encounter rate of microplastics/zooplankton was 5%, 15%, 34%, 49%, and 120% for Net I, and 8%, 21%, 47%, 60%, and 143% for Net II for copepods, chaetognaths, jellyfish, shrimp, and fish larvae, respectively. The average abundance of microplastics that were ingested by zooplankton was 4.1 pieces/m3 for Net I and 131.5 pieces/m3 for Net II.

Xiaoxia Sun, Qingjie Li, Mingliang Zhu, Junhua Liang, Shan Zheng, Yongfang Zhao, Marine Pollution Bulletin, Volume 115, Issues 1–2, 15 February 2017, Pages 217–224

The article

Microplastic pollution in the marine waters and sediments of Hong Kong

The presence of plastic waste with a diameter of less than 5 mm (“microplastics”) in marine environments has prompted increasing concern in recent years, both locally and globally. We conducted seasonal surveys of microplastic pollution in the surface waters and sediments from Deep Bay, Tolo Harbor, Tsing Yi, and Victoria Harbor in Hong Kong between June 2015 and March 2016. The average concentrations of microplastics in local coastal waters and sediments respectively ranged from 51 to 27,909 particles per 100 m3 and 49 to 279 particles per kilogram. Microplastics of different shapes (mainly fragments, lines, fibers, and pellets) were identified as polypropylene, low-density polyethylene, high-density polyethylene, a blend of polypropylene and ethylene propylene, and styrene acrylonitrile by means of Attenuated Total Reflectance – Fourier Transform Infrared Spectroscopy. This is the first comprehensive study to assess the spatial and temporal variations of microplastic pollution in Hong Kong coastal regions.

Y.Y. Tsang, C.W. Mak, C. Liebich, S.W. Lam, E. T-P. Sze, K.M. Chan, Marine Pollution Bulletin, Volume 115, Issues 1–2, 15 February 2017, Pages 20–28

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