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Agricultural plastic greenhouse (PG) production can extend the growing season of crops to satisfy domestic consumption in countries such as China. Workers in PGs have potential higher phthalate exposure risks than the general population as phthalate accumulation has been observed in greenhouse soil, air, and crops. To date, biomonitoring tests of phthalates for the working population have not been carried out. To address this shortage, we conducted a pilot study in Shaanxi Province, China, among 35 healthy PG workers by follow-up recording their seasonal dietary habits and work activities and urine sample collection and measurement between 2018 and 2019. The objectives were to uncover the association between phthalate metabolites and the population characteristics, seasonal and diurnal variations and causes, and to estimate exposure risks and contributions of exposure pathways from PG production systems. A total of 13 phthalate metabolite concentrations (Σ 13 phthalate metabolites) ranged from 102 to 781 (5th-95th) ng/mL (median: 300 ng/mL). Mono-n-butyl phthalate (MNBP) made up 51.3% of Σ 13 phthalate metabolites, followed by the sum of four di-2-ethylhexyl phthalate (DEHP) metabolites (24.2%), mono-2-isobutyl phthalate (MIBP) (13.4%), and mono-ethyl phthalate (MEP) (9.8%). The concentrations of MNBP and MIBP in summer were significantly higher than the levels in winter (p < 0.0001). A total of 62.3% of the PG worker population was shown to have exposure risks, and the proportion was as high as 79.4% in summer. Phthalate exposure of the workers from PG production systems constituted over 20% of the total creatinine-based daily intake, and consuming vegetables and fruit planted in PGs and inhalation in PGs were the two largest exposure pathways. Our findings demonstrate that it is important to protect workers in PGs from phthalate exposure risks, and phasing out the use of plastic materials containing phthalates in PGs is imperative, to guarantee food safety in PGs. [Display omitted] • We recorded seasonal urinary phthalates in the workers in plastic greenhouses (PGs). • The workers exhibited higher MNBP concentrations than the levels in general adults. • The MNBP concentrations in summer were significantly higher than the level in winter. • Over 60% of the workers was shown phthalate exposure risks, nearly 80% in summer. • Phthalate exposure from PG systems constituted over 20% of the total daily intake. [ABSTRACT FROM AUTHOR]

Phthalate pollution in soil and vegetables in plastic agricultural greenhouses has attracted wide concern. Investigating airborne phthalates in this environment can improve understanding of air-soil or air-vegetable phthalate migration. However, studies of phthalates in plastic agricultural greenhouse air are rare. To fill this gap, 25 gas-phase and 23 particle-phase samples were collected from 12 typical plastic greenhouses in Shaanxi. 16 types of phthalates were measured by a gas chromatography-mass spectrometry system (GC-MS) to analyse their pollution features and variations. Results showed that in the air of the plastic greenhouses, the median concentration of the sum of sixteen type phthalates (∑ 16 phthalates) was 5305 ng m−3, with 5th-95th value of 1214–9616 ng m−3. Phthalates in gas-phase samples were over 100 times higher than the levels in particle-phase samples. Air phthalate concentrations in the plastic greenhouses were higher than those in the control groups (P < 0.05). Air bis (2-ethylhexyl) phthalate (DEHP) and di-n-butyl phthalate (DnBP) accounted for 66.9% and 29.3% of total ∑ 16 phthalate concentrations, respectively. Air phthalate concentrations in the plastic greenhouses in winter were 1.1–5.3 times higher than the levels in summer respectively (P < 0.05). Gas-particle partition coefficients (K P) values of DEHP in summer (median of 1.52 × 10−4 m3 μg−1) were higher than K P values of DnBP in summer (0.60 × 10−4 m3 μg−1). Log-transformed K P values of DnBP and DEHP were linear correlated to the reciprocal of air temperatures, respectively (P < 0.05). Image 1 • We studied 16 types of phthalates in plastic greenhouse (PG) air. • Phthalates in gas-phase samples were over 100 times of those in particle-phase. • The sum of DEHP and DnBP was over 90% of total Σ 16 phthalates in air of PGs. • Phthalates in PG air in winter were 1.0–6.7 times higher than those in summer. • Log K P values of air DEHP and DnBP were linear correlated to 1/ T (P < 0.05). [ABSTRACT FROM AUTHOR]

• We compared soil comprehensive quality between vegetable and fruit greenhouses. • We adopted minimum dataset and modified Nemerow index for soil quality assessments. • Fertility quality more impacts the greenhouse soil than environmental factors do. • High EC and low SOM were main factors to reduce the fertility of greenhouse soil. • The accumulation of Cd and Hg in topsoil threats soil environment quality. The increasing demand of fruits and vegetables has resulted in the rapid growth of plastic greenhouse production (PGP) systems worldwide. A comprehensive assessment method considering both soil fertility and environmental safety is necessary for the sustainable development of PGP systems. A total of 92 vegetable greenhouses in Jingyang County and 28 fruit greenhouses in Dali County in Shaanxi Province, China, were selected for comparing the changes of soil quality under two cultivation patterns. The soil comprehensive quality index (SQI) in Jingyang (0.53) was significantly higher than that in Dali (0.46) (p < 0.05). A significant correlation was found between the SQI and the soil fertility index (SFI) (p < 0.01), suggesting that the SQI was mainly dependent on the soil fertility level in greenhouses. The primary limiting factors of the SFI in PGP in Jingyang and Dali were low soil organic matter content (19.57 g kg−1) and high electrical conductivity (1303 μS cm−1), respectively, indicating that soil in greenhouses in Jingyang and Dali might experience nutrient deficiencies and soil salinity accumulation problems, respectively. Cd and Hg were main limiting factors of soil environmental index (SEI), especially Hg. The SEI in Dali (0.74) was significantly lower than that in Jingyang (0.81) due to differences in the geo-accumulation indexes of heavy metals in the topsoil in greenhouses. Considering that no significant difference was found in the SFI between two study areas, the SEI is likely responsible for the regional differences in the SQI in PGP. The negative correlation of the SEI with the cultivation ages of plasticulture indicated that heavy metal accumulation problems would be the primary limiting factor of the SQI in the future if greenhouses cannot be managed appropriately. Our study provides data support for soil quality management in PGP systems. [ABSTRACT FROM AUTHOR]