Study On Urinary Health Risk Of Nano Calcium Carbonate In Drinking Boiled Water

People in China have the habit of drinking boiled water since ancient times.The scale problem caused by boiling water is prominent,which leads to the doubts of t drinking water from residents: Is there a relationship between the scale produced in high hardness water and the generation of urinary stones?Although animal experiments have shown that drinking high-hardness water does not lead to the formation of urinary stones,some epidemiological investigations have found that there is a certain correlation between the hardness of drinking water and urinary stones.Existing studies have found that nanocalcium carbonate and micro-calcium carbonate can be formed in the boiling process of high-hardness water.Animal experimental studies have shown that orally ingested nanocalcium carbonate can enter the blood circulation,and reach various tissues and organs of the body with the blood circulation.In addition,when nano-calcium carbonate is used as a drug carrier,the bioabsorption rate of nanoparticles is faster and can be accumulated in various tissues and organs for at least one month.Therefore,in order to explore the correlation between scale and urinary stones and provide experimental basis for t improving the quality of drinking water,the effects of nano calcium carbonate in scale particles on the formation of urinary calculi were studied by constant component method and cell experiment.The results of urinary stone composition analysis show that calcium oxalate is the main component of most urinary stones.Therefore,in order to explore the correlation between nano-scale calcium carbonate particles and calcium oxalate,the artificial urine was used to simulate the urinary environment in vitro,and nano calcium carbonate was added to the artificial urine under different reaction conditions.The possibility and transformation mechanism of nano calcium carbonate to calcium oxalate were determined by measuring the material composition,crystal structure and functional groups of particles.Based on the analysis of surface morphology,particle size distribution and particle size change,the effect of nano calcium carbonate on the growth of calcium oxalate was explored.In addition,this paper also detected the activity damage,protein content changes and oxidative stress level of renal cancer cells caused by different concentrations of nano-calcium carbonate.The effects of nano-calcium carbonate and calcium oxalate on renal cell carcinoma cell membrane were investigated.Based on the above research,this paper explored whether nano-calcium carbonate in high-scale water could promote the formation of urinary stones.The main conclusions of this study are as follows:(1)In the simulated urinary environment in vitro,the nano-calcium carbonate was transformed into calcium oxalate through the coupling effect of dissolution-precipitation and combined with the generated calcium oxalate to form the nano-calcium carbonatecalcium oxalate composite particles.The calcium oxalate on the surface of the composite particles in the form of layered growth,and the particle size distribution showed a positive skewed normal distribution.Most of the particle sizes was between 20-30 μm,and the average particle size and surface roughness of the particles increased with the increase of reaction time.Therefore,in the urinary environment,nano-calcium carbonate will transform to calcium oxalate and its composite particles will continue to increase,which increases the possibility of calcium oxalate forming stones.(2)After co-culture of nano-calcium carbonate,with renal cancer cells for 24 h,the toxic effect of nano-calcium carbonate on cells was studied.It was found that under the effect of nano-calcium carbonate,the activity of renal cancer cells decreased,the cell morphology changed,and the intracellular total protein content decreased.In addition,the increase of intracellular oxidative indexes such as reactive oxygen species and malondialdehyde and the decrease of antioxidant indexes such as superoxide dismutase and reduced glutathione indicated that cells were subjected to slight oxidative stress.Compared with micro-calcium carbonate,nano-calcium carbonate was found to be more toxic to kidney cancer cells,causing higher levels of oxidative stress.The damage caused by nano-calcium carbonate on renal cancer cells provided organic conditions for the formation of urinary stones.(3)By analyzing the cell membrane damage of and nano-calcium carbonate to renal cancer cells,it was found that the oxidative stress caused by nano-calcium carbonate on cells led to the increased of cell membrane permeability and destroyed the cell membrane integrity of some cells.The damage to cell membrane caused by micro-calcium carbonate was much less than that caused by nano-calcium carbonate.After the membrane was damaged,some substances that promoted the formation of urinary calculi can be leaked out of the cell through the membrane,changed the structure of the cell membrane,and increased the crystal adhesion sites on the cell membrane,and leading to the attachment of nano-calcium carbonate and calcium oxalate to on the surface of the cell membrane and the formation of different degrees of aggregation.The damage of nano-calcium carbonate the cell membrane increased the adhesion of urinary stones on the surface of the cell membrane,and reduced the scouring and loss of calcium oxalate particles in urine.