Accumulation of steroid hormones in soil and its adjacent aquatic environment from a typical intensive vegetable cultivation of North China.

Steroid hormones released from manure agricultural application are a matter of global concern. The residual levels of steroid hormones were studied in a typical intensive vegetable cultivation area in northeast China, with a long history of heavy manure application. Seven steroids (estrone, 17α-estradiol, 17ß-estradiol, estriol, testosterone, androstendione and progesterone) were analyzed from soil sampled from vegetable greenhouses, from sediments and water from the adjacent drainage ditch and from the groundwater. The results showed that target steroids were detected in the soil samples, with detection frequencies varying from 3.13 to 100%. The steroid concentrations varied substantially in soils, ranging from below the detection limit to 109.7µg·kg(-1). Three steroids-progesterone, androstendione and estrone-were found to have relatively high residue concentrations in soil, with maximum concentrations of 109.7, 9.83 and 13.30µg·kg(-1), respectively. In adjacent groundwater, all the steroids, with the exception of estrone, were detected in one or more of the 13 groundwater samples. The concentrations of steroids in groundwater ranged from below the method detection limit to 2.38ng·L(-1). Six of the seven (excluding androstendione) were detected in drainage ditch water samples, with concentrations ranging from below the detection limit to 14ng·L(-1). Progesterone, androstendione and estrone accumulated relatively easily in soils; their concentrations in groundwater were lower than those of other steroids. The concentrations of testosterone and estriol were relatively low in soil, while in groundwater were higher than those of other steroids. The residual levels of steroids in soil and groundwater showed a clear spatial variation in the study area. The residual levels of steroid hormones in soil varied substantially between differently planted greenhouses.

[Sorption of 17beta-estradiol to soils and sediment and influence of pig manure DOM].

Natural steroid estrogens such as 17beta-estradiol (E2) with low concentrations (ng x L(-1)) can adversely affect the reproductive health of aquatic organisms. Batch equilibrium experiments were conducted to quantify the sorption of E2 to two agricultural soils and a river sediment from different physiographic regions in northern China, a critical step in predicting transport of estrogens in runoff from agricultural fields. Meanwhile, the effect of pig manure and its compost borne dissolved organic matter (DOM) on E2 sorption was investigated. The Freundlich isotherm provided a good fit to model the sorption of E2 to agricultural soils and the sediment (R2 > 0.76). E2 adsorption nonlinearity was found for alluvial soil, black soil and the sediment, most isotherm deviation from linearity occurred in black soil (n = 0.74). The sorption of E2 to agricultural soil and sediment was correlated to the organic carbon content of each soil/sediment (P<0.05) with K(f) values ranging from 26.2 to 57.5. It was also found that the presence of DOM decreased estrogen sorption in soils and sediment, especially manure compost borne DOM. These results suggest that E2 was mostly adsorbed on organic matter in soil and sediment, and coexisted pig manure DOM could increase mobility at low concentration level and enhance the risk of E2 transport to ground and surface waters.

Migration of natural estrogens around a concentrated dairy-feeding operation.

Concentrated animal feeding operations have been recognized as one of the most important contributors of natural estrogens which show significant endocrine-disrupting properties in aquatic environments. In this study, the concentrations of 17α-estradiol (17α-E2), 17ß-estradiol (17ß-E2), estrone (E1), and estriol (E3) in several matrices, including soils (surface and deep), sediments (surface and deep), and groundwaters, around a typical dairy farm were surveyed using gas chromatography/mass spectrometry. Of the two farmlands, surface and subsurface sediments in waste lagoon and along effluent drainage drench, the concentrations of 17α-E2, 17ß-E2, and E1 ranged from below detection limit to the highest level of 6.60 µg/kg, except that E3 was not detectable. Three estrogens of 17α-E2, 17ß-E2, and E1 with the concentrations of 3.18-31.61 ng/L were observed in two groundwater samples. The results clearly demonstrated the vertical migration and horizontal transport of estrogens in the investigated area. Within 750-m distance, it was observed the attenuation of 17α-E2, 17ß-E2, and E1 along the effluent route and the horizontal migration of estrogens was less than 1,350 m in this survey.

[GIS-based analysis of the land suitability for manure application in the northeastern provinces].

As an important industrial and grain production base of China, livestock and poultry industry have been rapidly developed in the northeastern provinces. With the rapid increasing amount of animal production, how to handle the huge amount of animal manure has become a critical issue for local government. A quantitative analysis based on geographic information system (GIS) combining the biophysical, environmental, social and economic factors was applied to determine the land suitability for manure application in the northeastern provinces. The results show that a farmland area of 211942.7 km2, accounting for 78.9% of the cultivated land in three northeastern provinces, is estimated to be suitable for manure application. The suitable farmlands are mostly distributed in Heilongjiang and Jilin provinces. Proximity to residential area, water body and roads are identified as the primary factors influencing the manure application, while rainfall is the main factor to generate discrepancies in different areas. Furthermore, the future potential capacity for animal production in three provinces was forecasted based on the areas of suitable land and the population of existing livestock production. Among 36 cities of three provinces, the big variation is observed, Siping City is overproducing 1.813 million heads of pig unit at present, but Qiqihaer City still has the potential to rear 11.203 million heads of pig unit. Overall, eastern region of the study area holds the high potential for animal production with a surplus capacity of 2.842 million heads of pig unit, the potential of the typical mountain and forest areas is only 10% of eastern region, however. In contrast, in half of western region (central Liaoning province and central Jilin Province), their animal populations have exceeded the land carrying capacity. Therefore, we strongly suggest a site-specific animal production and manure application guide to achieve a sustainable development of livestock production in the northeastern provinces.

Cadmium in animal production and its potential hazard on Beijing and Fuxin farmlands.

A random sample of pairs of animal feeds and manures were collected from 215 animal barns in Beijing and Fuxin regions of China. The concentrations of Cd in manures and feeds ranged from non-detectable to 129.8 mg/kg dry weight and non-detectable to 31 mg/kg dry weight, respectively. The concentrations of Cd in pig, dairy cow and chicken manures were positively correlated to those in their feeds. About 30% of the manure samples contained Cd concentrations higher than the upper limit for use in farmlands, and pig and chicken manures might be the primary contributors of Cd to farmlands. The farmlands in Beijing and around the Fuxin Downtown areas would exceed the soil quality criteria within several decades according to current manure Cd loading rates. Undoubtedly, more scientific animal production and manure management practices to minimize soil pollution risks are necessary for the two regions.

[Effects of particle-sizes, pH and organic matter on adsorption and desorption of mercury to sediments in the Songhua River].

The present study aims to further reveal the environmental behavior of mercury on sediments surface. Effects of particle-sizes, pH and concentrations of dissolved organic matter (DOM) on mercury adsorption and desorption to the surface of sediments in the Songhua River were investigated by simulation experiments. A distinct variety of absorption ability among sediments with different particle-sizes was observed. Under this experimental condition, the absorption ability increased inversely with particle-size of sediments. In all absorption systems, mercury adsorption was enhanced when pH increased from 3.5 to 4.5, while mercury adsorption was inhibited significantly with the increasing of pH when pH values were above 4.5. With the increasing of pH values, the desorption of mercury presented a decreasing-increasing trend, the minimum desorption occurred at pH 5. Citric acid inhibited the mercury adsorption, and the intensity was correlated with mercury concentrations. Effects of citric acid on desorption of mercury were also apparently. With the increasing of citric acid concentrations, its effect on desorption presented a trend as enhanced-inhibited-steadied. Therefore, the above factors affected the mercury adsorption and desorption obviously, and it was necessary to take these factors into consideration in conducting the rivers' mercury control and dealing with a sudden pollution incident.