Hospital laboratory wastewater has been considered to significantly change the degree of contamination of especially the hospital wastewater. The present study investigated the hospital clinical laboratory wastewater and the pollution loads were assessed for pathogens, heavy metals, and organic materials. Composite samples were collected from clinical laboratory wastewater of a 350-bed hospital for a six-month period. Analyses for pH, TSS (Total Suspended Solid), BOD (Biochemical Oxygen Demand), COD (Chemical Oxygen Demand), PO4-P, and Cl as well as heavy metals (Cd, Pb, Zn, Cu, Cr, Co, Ni, Al, and Mn) were made in order to physiochemical properties of the samples. Bacterial isolation (<i>Pseudomonas aeruginosa</i>, <i>Escherichia coli</i>, <i>Acinetobaumanii</i>, CNS—Coagulase- Negative <i>Staphylococcus</i>) and antigen-antibody analyses were conducted in order to find the microbiological pollution load of the wastewater. As a result of the study it was found that the hospital clinical laboratory wastewater was alkaline and COD/BOD ratio reached to a range of 10 - 12 in the wastewater. It was concluded that although the heavy metal concentrations were within the sewage discharge limits the said levels could pose health risk. It was also found that the wastewater entailed health risk due to pathogens.
Although the recent years witnessed increased focus on hospital waste management throughout the world, the number of studies as regards management and treatment of wastewater due to hospital and biochemistry, microbiology etc. clinical laboratories remained limited. Hospital wastewater includes macro- and micro-pollutants of wide concentration range from laboratories, research units, operation rooms, units, where medicine and nutrition solutions are prepared, and polyclinics [
Studies have suggested that even the pretreatment of hospital wastewater prior to discharge to domestic wastewater sewage systems for treatment might not be a sufficient solution due to the micro-pollutant content of hospital wastewater [
Infected wastewater is generally originated from water consumption of patients and analyses of patient urine, feces, and blood samples. Today viral diseases rather than infectious diseases caused by bacteria and parasites are at the forefront. Viral infection due to viral hepatitis is the leading viral disease. Mostly transmitted by direct blood contact among human beings, today hepatitis B, hepatitis C, and HIV infections are life threatening yet easy-to- prevent infections if necessary precautions are taken. Viral hepatitis agents are contained in a substantial part of medical waste from public and private hospital laboratories and other private and public laboratories, and public and private dialysis centers. Hospital laboratory wastewater is considered a mixture of pathogen microorganisms. The genetic structure of such microorganisms may be altered by the direct or indirect effect of wastewater components and lead to bacteria with high antibiotic resistance [
Medical wastewater originated from hospital laboratories has the potential to pose serious threat in terms of spread and contagiousness of infectious diseases for patients in the healthcare units, hospital employees, society, and the environment. The medical wastewater of hospitals and laboratories contains such pathogen, infectious agent bacteria as Salmonella spp., Shigella spp. as well as many other different microorganisms with multiple drug resistance (MDR) (Pseudomonas spp., Acinetobacter spp., Enterococcus spp., and S. aureus spp. etc.). Previous studies frequently isolated such frequently occurring nosocomial infectious agents as Bacillus spp., Staphylococcus spp., Streptococcus spp. (5% - 10%), E. coli (Escherichia coli), Pseudomonas aeruginosa, and Candida albicans as well as other less frequent nosocomial pathogens as Klebsiella spp., Proteus spp., and Enterobacter spp. [
The fact that hospital wastewater contains enterobacteria and enteric pathogens, poses a risk for public health. Today, the marked increase in antibiotic resistance of infectious agent pathogen bacteria seen both in nosocomial and community-acquired infections is one of the most important problems [
Studies suggested that hospital wastewater was generally of similar nature with domestic wastewater [
This research was conducted at the Central Laboratory of 350-bed capacity Keçiören Training and Research Hospital (Ankara, Turkey). Patients and samples are assessed via advanced technological applications in the hospital under Pathology, Radiology, Biochemistry, and Microbiology branches. A monthly average of 200 thousand biochemical and serological tests, and 20 thousand culture and manual tests are conducted at the central laboratory of the hospital. Based on an average 8-hour operation time, the devices used in the clinical laboratory of the hospital produce 561.06 liters of wastewater daily (
Wastewater from laboratory environment is collected in a storage tank via closed loop collection line. The wastewater is discharged to sewage system after disinfection and neutralization process. In the scope of the experimental studies, wastewater samples were collected from the storage tank as 24-hour composite samples. Monthly sample collection continued for 6 months. The samples were carried to the laboratory in storage boxes, which comply with the Standard Methods [
Cadmium (Cd), lead (Pb), zinc (Zn), copper (Cu), chromium (Cr), cobalt (Co), nickel (Ni), aluminum (Al), and manganese (Mn) analyses were made in the scope of the study. Samples collected for heavy metal analyses were placed in polyethylene vials and the medium was acidified by adding 1% HNHNO3. The biological activity of organisms and bacteria was thus terminated in order to transformation into forms other than metals. Samples were kept in fridge at −80˚C [
Device | Wastewater amount (L/day) |
---|---|
Routine Biochemistry | 466.7 |
Immunoassay devices | 44.7 |
Complete Blood Device | 33.3 |
Urine Analyzers | 8.3 |
Coagulation Devices | 5.83 |
HPLC and Chromatography | 2 |
Blood Gas | 0.23 |
TOTAL | 561.06 |
Agilent 7500 CXICP-MS device was used in metal analyses of water samples and the analyses were conducted according to the Standard Methods [
In order to determine the quantity of total bacteria in the collected water samples, 6 series of dilutions were prepared; upon which 1 ml from each sample were inoculated in agar with 5% sheep blood. The agar plates were incubated in aerobic environment for 24 to 48 hours at 37˚C. Furthermore, selective media were also inoculated besides agar with 5% sheep blood for determination of bacterial variety. For the purpose thereof, following inoculations, with the use of quantitative method, were conducted: Eosin Methylene Blue for determination of enteric bacteria, Bile Esculin Azide Agar with 100 mg/ml Azide for enterococci, Hektoen Enteric Agar and Chromogenic Salmonella plus Agar for Salmonella spp.-Shigella spp., Sabouraud Dextrose Agar for possible fungi growth, Specific Chromogenic Pseudomanas Agar for Pseudomonas spp., and finally Chromogenic E. coli Agar for E. coli. The inoculated media were incubated in aerobic environment for 24 to 48 hours at 37˚C. The media were inspected at 24th and 48th hours of incubation [
Bacterial suspensions were prepared in sterile tubes upon collection of preliminary information about bacteria through Gram Staining, Catalase Test for Gram positive bacteria and Oxidase Test for Gram Negative bacteria. The turbidity degree of suspensions were set to Mac Farland standard 0.5 by means of DensiCheck (BioMerieux) and advance identification processes were held using Vitec 2 GP card for Gram positive bacteria, and Vitec 2 GN card for Gram negative bacteria at Vitec 2 Compact (Biomerieux) automated system. The bacteria were identified in terms of types and species [
Antigen and Antibody determination: HbsAg, Anti-HCV, Anti-HIV, Toxoplasma IgM, Rubella IgM AND CMV IgM concentration was measured with automatic diagnostic system (Architect system, Abbott Diagnostics, U.S.A). The Architect system HbsAg, Anti-HCV, Anti-HIV, Toxoplasma IgM, Rubella IgM, CMV IgM assays, uses chemiluminescent immunoassay (CLIA) technology for the quantitative determination of hepatitis B surface antigen and antibody, hepatitis C antibody, HIV p24 antigen and HIV-1 and HIV-2 antibody, Toxoplasma gondii against formed IgM antibody, Rubella virus IgM antibody, CMV IgM antibody.
The findings of the physiochemical and heavy metal analyses for determining the characterization of hospital clinical laboratory wastewater were provided in
It was reported that hospital wastewater had generally similar characteristics with domestic wastewater as regards BOD, COD, and SS concentrations [
Cadmium (Cd), lead (Pb), zinc (Zn), copper (Cu), chromium (Cr), cobalt (Co), nickel (Ni), aluminum (Al), and manganese (Mn) in the hospital laboratory wastewater were measured for a six-month period in the scope of the study. Heavy metal concentrations based on analyses on monthly collected samples were provided in
Limit values that must be met by wastewater to be discharged to sewage system were determined pursuant to the Regulation of Wastewater Discharge into Sewage System in force in Turkey and
Parameters | January | February | March | April | May | June | Max. | Min. | Avg. |
---|---|---|---|---|---|---|---|---|---|
pH | 7.9 | 8.2 | 8.7 | 9.0 | 9.4 | 8.9 | 9.4 | 7.9 | 8.7 |
Cl (mmol/L) | 129 | 130 | 138 | 136 | 141 | 156 | 156 | 129 | 138.3 |
PO4-P (mg/L) | 15 | 16 | 21 | 25 | 28 | 30 | 30 | 15 | 22.5 |
BOD (mg/L) | 63 | 74 | 89 | 103 | 101 | 112 | 112 | 63 | 75.3 |
COD (mg/L) | 769 | 865 | 896 | 925 | 1127 | 1023 | 1127 | 769 | 934.2 |
TSS (mg/L) | 102 | 113 | 98 | 121 | 162 | 148 | 162 | 98 | 124 |
Parameters (mg/L) | January | February | March | April | May | June | Max. | Min. | Avg. |
---|---|---|---|---|---|---|---|---|---|
Al | 0.056 | 0.056 | 0.061 | 0.071 | 0.046 | 0.065 | 0.071 | 0.046 | 0.059 |
Cr | 0.076 | 0.076 | 0.075 | 0.095 | 0.034 | 0.082 | 0.095 | 0.034 | 0.073 |
Mn | 0.005 | 0.005 | 0.005 | 0.004 | 0.003 | 0.003 | 0.005 | 0.003 | 0.004 |
Co | 0.0002 | 0.0002 | 0.0002 | 0.0003 | 0.0004 | 0.0002 | 0.0004 | 0.0002 | 0.0003 |
Ni | 0.0006 | 0.0006 | 0.0006 | 0.0009 | 0.0007 | 0.0008 | 0.0009 | 0.0006 | 0.0007 |
Cu | 0.689 | 0.89 | 0.703 | 0.854 | 0.764 | 0.443 | 0.854 | 0.443 | 0.690 |
Zn | 0.004 | 0.004 | 0.002 | 0.006 | 0.007 | 0.001 | 0.007 | 0.001 | 0.004 |
Cd | 0.031 | 0.031 | 0.024 | 0.019 | 0.017 | 0.024 | 0.031 | 0.017 | 0.024 |
Pb | 0.084 | 0.084 | 0.075 | 0.057 | 0.068 | 0.056 | 0.084 | 0.056 | 0.071 |
World Health Organization (WHO) [
Principally the chemical and analysis kits accounted for the heavy metal concentrations in the wastewater of hospital clinical laboratories. Several studies on hospital wastewater reported such heavy metals as Pb, Hg, Pt, Cd, and Sr in the wastewater [
Bacterial isolation and count were conducted in the samples collected for the purpose of the study for Pseudomonas aeruginosa, Escherichia coli, Acinetobaumanii, CNS (Coagulase-negative staphylococcus) and the results were provided in
E. coli levels varied between 9 × 102 and 8 × 104 cfu/ml ranges in clinical laboratory wastewater samples. The change in bacteria levels during the six-month period was as a result of the difference in patient serum numbers. Different studies reported total coliform numbers in hospital wastewater as 106 (colony/100ml) [
Antigen and antibody analyses were made for the wastewater samples. Distribution of antigens and antibodies by month was provided in
Parameter (mg/L) | TSE 266 | WHO | EPA | Present Ptudy |
---|---|---|---|---|
Cd | 0.01 | 0.01 | 0.01 | 0.024 |
Cr | 0.05 | 0.05 | 0.05 | 0.073 |
Co | 0.01 | 0.01 | 0.01 | 0.0003 |
Cu | 3.00 | - | - | 0.690 |
Mn | 0,10 | 0.05 | 0.05 | 0.004 |
Ni | 0.02 | 0.02 | 0.02 | 0.0007 |
Pb | 0.05 | 0.05 | 0.05 | 0.071 |
Zn | 5.00 | - | 5.00 | 0.004 |
January | February | March | April | May | June | |
---|---|---|---|---|---|---|
Pseudomonas aeruginosa | 9 × 106 | 5 × 106 | 3 × 105 | 2 × 104 | 4 × 106 | 6 × 105 |
Escherichia coli | 3 × 103 | 6 × 104 | 2 × 104 | 9 × 102 | 7 × 103 | 8 × 104 |
Acinetobaumanii | 5 × 104 | 6 × 106 | 4 × 106 | 6 × 105 | 5 × 105 | 3 × 106 |
CNS (Coagulase-negative staphylococcus) | 2 × 102 | 3 × 102 | 2 × 103 | 7 × 101 | 5 × 102 | 4 × 102 |
January | February | March | April | May | June | |
---|---|---|---|---|---|---|
Anti-HCV | − | − | − | − | + | + |
Anti-HIV | - | − | − | − | − | − |
HBsAg | + | − | − | + | + | − |
HAV-IgM | + | + | − | − | − | − |
Toxoplazma-IgM | + | − | − | − | − | − |
Rubella-IgM | − | − | − | + | − | − |
CMV-IgM | − | − | + | + | − | − |
+Reactive, −Nonreactive.
The present study aimed to investigate the general pollution load of hospital clinical laboratory wastewater, first of its kind in the relevant literature. Wastewater of the clinical laboratory of a 350-bed hospital was analyzed for a six-month observation period. As a result of the study it was found that COD/BOD ratio was very high in the hospital clinical laboratory wastewater. Furthermore, it was seen that concentrations of heavy metal that could be hazardous for human health were above the standard limits. Upon the analyses it was seen that there were high levels of pathogen organisms in the wastewater. Moreover, despite the viral pathogens were not included in the study, the occurrence of IgM antibodies was an indication of pathogens in the wastewater. The results of the present study clearly demonstrated that the hospital clinical laboratory wastewater substantially increased the pollution load of the entire hospital wastewater.
Beril Salman Akin, (2016) Contaminant Properties of Hospital Clinical Laboratory Wastewater: A Physiochemical and Microbiological Assessment. Journal of Environmental Protection,07,635-642. doi: 10.4236/jep.2016.75057