Polycyclic Aromatic Hydrocarbons in Soil at Different Depths under a Long-Term Experiment Depending on Fertilization

In order to investigate the pollution status of polycyclic aromatic hydrocarbons (PAHs) in the agricultural soil, 240 agricultural soil topsoil samples were collected from nine Pearl River Delta cities from June to September 2019. In addition, 72 samples were collected for vertical soil profiles, which soil profiles were excavated to a depth of 80 cm. After sample preparation, GC-MS was used for the separation of compounds on a HP-5MS quartz capillary column. ArcGIS software was used to map the spatial distribution. Health risk assessment was conducted using USEPA standard. The results showed that the total concentration of 16 PAHs ranged from 43.4 to 5630 ng/g, with an average of 219 ng/g. The spatial distribution showed that most of the seriously polluted areas were in the coastal area, near the port, and there was point source pollution in the Gaoming of Foshan. Vertically distributed display Zhuhai, Jiangmen, Zhaoqing, Shenzhen and Dongguan increased and then decreased from bottom to bottom, showing a low-high-low pattern, the concentration of PAHs in Zhongshan and Foshan decreased with the soil depth, while the concentration of PAHs in Guangzhou and Huizhou was enriched with human activities. The PAHs components in soil samples were mainly medium and high rings (4–6 rings). The analysis of the origin of PAH in soil samples showed that the mixture of incomplete combustion sources of fossil fuels such as coal and biomass and traffic emission sources were the main sources of soil PAHs. A small amount can be attributed to oil sources such as oil spills. The human health risk assessment showed no cancer risk for children, while for adults, may cause a potential risk of cancer, which needs to be noticed. Spearman correlation analysis showed that PAH content was significantly correlated with SOC (p < 0.01) and pH (p < 0.05). Port transport, road emissions and industrial production make the area a pollution hot topic, and supervision should be strengthened to protect the environment and food safety.

Section: Resultsmentioning

confidence: 99%

Polycyclic Aromatic Hydrocarbons Pollution Characteristics in Agricultural Soils of the Pearl River Delta Region, China

Cai

Yao

Huang

et al. 2022

“…Soil is a porous and complex mixture, containing inorganic elements and compounds formed and anthropogenic pollutants [ 33 ]. Numerous factors can influence the rate and extent of PAH biodegradation in soil [ 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 ], including organic matter content, nutrient content, fertilization, C:N:P ratio, microbial counts, electron acceptors, temperature, moisture, pH, and oxygen concentration. PAHs are removed from soil both with [ 42 ] and without microbial involvement [ 43 ].…”

Section: Discussionmentioning

confidence: 99%

The Influence of Crops on the Content of Polycyclic Aromatic Hydrocarbons in Soil Fertilized with Manure and Mineral Fertilizers

Mackiewicz-Walec

Krzebietke

Sienkiewicz

2022

Polycyclic aromatic hydrocarbons (PAHs) are mainly accumulated in soil. Plants secrete enzymes that transform or biodegrade PAHs in soil. Some plant species are more effective in stimulating the biodegradation of these pollutants than other species. This study was undertaken to evaluate the influence of crop rotation on PAH concentrations in soil. Four crops were grown in rotation: sugar beets, spring barley, maize, and spring wheat. Soil samples for the study were obtained from a long-term field experiment established in 1986 in Bałcyny, Poland. The concentrations of PAHs were analyzed in soil samples gathered over a period of 12 years (1998–2009). An attempt was made to evaluate the effect of crop rotation (sugar beets, spring barley, maize, and spring wheat) on PAH concentrations in soil. The content of PAHs in soil samples was measured by gas chromatography with flame ionization detection. Data were processed statistically by repeated measures ANOVA. The concentrations of ∑16 PAHs were lowest in soil after sugar beet cultivation, and highest in soil after maize cultivation. It can be concluded that maize was the plant with the greatest adverse effect on the content of heavy PAH in the soil, a completely different effect can be attributed to spring wheat, which has always been shown to reduce the content of heavy PAH in the soil. Weather conditions affected PAHs levels in soil, and PAH content was highest in soil samples collected in a year with the driest growing season. This arrangement suggests a greater influence of weather conditions than of the cultivated plant.

“…Polycyclic aromatic hydrocarbons (PAHs) are considered to be especially toxic to humans, likewise to plants, microorganisms and other living organisms. PAH toxicity is a well-known fact, especially its ability to cause cancer [1][2][3][4][5]. Polycyclic aromatic hydrocarbons belong to the group of persistent organic pollutants.…”

Section: Introductionmentioning

confidence: 99%

The Effect of Spring Barley Fertilization on the Content of Polycyclic Aromatic Hydrocarbons, Microbial Counts and Enzymatic Activity in Soil

Mackiewicz-Walec

Krzebietke

Borowik

et al. 2023

Self Cite

Soil-dwelling microorganisms play an important role in the environment by decomposing organic matter, degrading toxic compounds and participating in the nutrient cycle. The microbiological properties of soil are determined mainly by the soil pH, granulometric composition, temperature and organic carbon content. In agricultural soils, these parameters are modified by agronomic operations, in particular fertilization. Soil enzymes participate in nutrient cycling and they are regarded as sensitive indicators of microbial activity and changes in the soil environment. The aim of the present study was to determine whether PAH content in soil is associated with the microbial activity and biochemical properties of soil during the growing season of spring barley treated with manure and mineral fertilizers. Soil samples for analysis were collected on four dates in 2015 from a long-term field experiment established in 1986 in Bałcyny near Ostróda (Poland). The total content of PAHs was lowest in August (194.8 µg kg−1) and highest in May (484.6 µg kg−1), whereas the concentrations of heavier weight PAHs was highest in September (158.3 µg kg−1). The study demonstrated that weather conditions and microbial activity induced considerable seasonal variations in PAHs content. Manure increased the content of organic carbon and total nitrogen, the abundance of organotrophic, ammonifying and nitrogen-fixing bacteria, actinobacteria and fungi and enhanced the activity of soil enzymes, including dehydrogenases, catalase, urease, acid phosphatase and alkaline phosphatase.