Impact of acetyl tributyl citrate on gonadal sex differentiation and expression of biomarker genes for endocrine disruption in Japanese medaka.

Plasticizers are broadly classified as phthalate or nonphthalate. Recently, acetyl tributyl citrate (ATBC), an environmentally friendly nonphthalate plasticizer, was revealed to have the ability to disrupt thyroid hormone activity in fish species. Therefore, we aimed to assess whether ATBC exhibits any sex hormone (i.e., androgenic or estrogenic) activities. First, we examined the effects of ATBC on gonadal sex differentiation. Subsequently, we analyzed the different expression of biomarker genes that respond to endocrine-disrupting chemicals (EDCs) with sexual hormone activity in the liver. We observed normal testes and ovaries after both XX and XY medakas were exposed to ATBC, indicating that ATBC is not an EDCs with strong sex hormone activity and that it does not induce intersex (testis-to-ova or ovo-to-testis) or sex changes in Japanese medaka. The vitellogenin 1 (vtg1) and vitellogenin 2 (vtg2) mRNA expression levels in the liver of XX medakas were significantly reduced compared with those in the control group, whereas the expression levels of these genes in the liver of XY medakas remained unchanged. Finally, we examined the changes in the expression of biomarker genes that respond to EDCs with sex hormone activity in the gonads. The expression levels of biomarker genes did not differ significantly from that of the control group, although the expression levels of gsdf mRNA tended to increase while that of aromatase mRNA tended to decrease in the ovary of XX medakas following ATBC exposure. Conversely, the expression levels of gsdf and aromatase mRNAs in the testis of XY medakas remained unchanged. These results suggest that ATBC does not exhibit estrogenic activity, although it may have weak androgenic activity or no sexual hormone activity.

Microplastics accumulation and human health risk assessment of heavy metals in Marcia opima and Lingula anatina, Phuket.

The concerns over potential health risk from the consumption of Marcia opima (M. optima) and lingulata (Lingula anatina) contaminated by heavy metals (Cd, Pb and Zn) and microplastics in the eastern part of Phuket, Southern Thailand has been assessed. The abundance of microplastics in Marcia opima and Lingulata were 1.86 and 1.24 items/individual, respectively and followed the order: polyethylene terephthalate > polyester > polyvinyl alcohol and polyvinyl chloride. Integrated risk indices using the daily intake (EDIs) for heavy metals consumption (from 0.00001 to 0.00712 mg kg-1 per day) are not exceeded the standards set by the ministry of public health Thailand to pose potential carcinogenic health risk individually. The bioaccumulations and hazard quotient values (<1) showed no risk exists concerning the levels of exposure, however, monitoring heavy metals concentration and microplastic contaminations on a regular basis are necessary to prioritize the local people health from pollutants exposure.

Occurrence and distribution of microplastics in beach sediments along Phuket coastline.

Phuket is a popular tourism destination in Thailand. This study examined the distribution of microplastics found on beaches along the East and West coasts of Phuket including Tri Trang, Patong, Kalim, Chalong, Makham, and Rawai beaches. A total of 18 samples from a 0.5 m × 0.5 m quadrat at the intertidal zone were sorted into >300-µm and 20-300-µm size classes. For all sizes combined, the mean abundance was 188.3 ± 34.5 items kg-1. White (29.2%) and fiber (85.6%) were the most abundant plastic; and the polymer types based on µFTIR analysis were PET > PS > PP > PU > PVC > Epoxy with a great amount of cotton and regenerated cellulose also detected. Principal component analysis indicated the correlation between PET, regenerated cellulose, PP and PU with Chalong and Patong beaches, suggesting that highly visited tourist beaches with harbor activities, and a tourist departure point, are possible sources of microplastics.

Assessment of Knowledge, Attitude, and Practice in respect of Medical Waste Management among Healthcare Workers in Clinics.

Medical waste represents a significant health risk and an environmental pollution concern due to its hazardous characteristics. The knowledge and practice of healthcare personnel in respect of the disposal of medical waste is essential to perform effective medical waste management. Therefore, the aim of this study was to assess the knowledge, attitudes, and practices related to medical waste management among healthcare workers in clinics (medical and dental clinics, specialized medical, laboratory clinics, polyclinics, and midwifery clinics) in Phuket, Thailand. A cross-sectional study was designed with stratified-random sampling used to select the sample of 344 respondents from 172 clinics of which data were collected using face-to-face interviews. The results showed that the majority of respondents (87.2%) were female of whom 36.9% were aged (20-29), 52.0% had more than 5 years working experience, and 51.2% had participated in at least one training course regarding medical waste management. The overall scores for knowledge, attitude, and practice were at a high level (89.5%, 91.9%, and 92.2%, respectively). Significant and positive correlations were found between knowledge and attitude (r = 0.464), knowledge and practice (r = 0.396), and practice and attitude (r = 0.519). Statistical analysis using t tests and one-way analysis of variance showed that working experience and its duration were significant factors influencing good medical waste management practice. However, local authorities should implement a well-planned collection and transfer process for medical waste in order to reduce the risk of environmental pollution and the risk of infection or injury to healthcare workers and the general public.

Metal accumulation in the marine bivalve, Marcia optima collected from the coastal area of Phuket Bay, Thailand.

Metal contamination in seafood has raised public health concerns, especially for local residents who live in coastal areas. In this study, the levels of cadmium (Cd), lead (Pb), mercury (Hg), and zinc (Zn) were determined in the marine bivalve, Marcia optima, as well as in water, and sediment samples collected from the coastal area of Phuket Bay, Thailand. The results showed that metal concentrations in sediments (4.05-7.14, 16.68-18.13, 164-213 mg kg-1 for Cd, Pb, and Zn, respectively) and water samples (0.16-0.44, 0.15-0.26, and 0.32-0.48 mg L-1 for Cd, Pb, and Zn, respectively) were below the threshold effects concentration of the sediment quality guidelines for adverse effects to occur and the marine water quality standards of Thailand. A human risk assessment was performed and the results showed that the risks associated with M. optima consumption at Saphan Hin and Paklok were negligible for most of the metals studied, with the maximum estimated daily intake value being observed for Zn (0.00663 mg kg-1 per day) at Saphan Hin. In addition, Cd, Zn, Pb, and Hg would be unlikely to pose a risk to human health with a hazard quotient of less than 1, with only the bioaccumulation factor of Zn being detectable in both locations (0.034 and 0.026 at Saphan Hin and Paklok, respectively). However, continuous monitoring is encouraged to prevent the risks associated with the consumption of metal-contaminated seafood.

Effects of sugarcane waste-products on Cd and Zn fractionation and their uptake by sugarcane (Saccharum officinarum L.).

The effects of three sugarcane waste-products from an ethanol production plant on the fractionation of Cd and Zn in high Cd and Zn contaminated soil and metal accumulation in sugarcane (Saccharum officinarum L.) were studied, using the BCR sequential extraction and aqua regia extraction procedures. A pot experiment was performed for 4 months with four treatments: no-amendments (control), boiler ash (3% w/w), filter cake (3% w/w) and a combination of boiler ash and vinasse (1.5% + 1.5%, w/w). The results showed that all treatments reduced the most bioavailable concentrations of Cd and Zn (BCR1 + 2) in soils (4.0-9.6% and 5.5-6.3%, respectively) and metal uptake (µg) in the aboveground part of the sugarcane (up to 62% and 54% for Cd and Zn, respectively) as compared to the control. No visual symptoms of metal toxicity and no positive effect on the biomass production of sugarcane were observed. Both Cd and Zn were accumulated mainly in the underground parts of the sugarcane (root > shoot ≥ underground sett > leaf; and root > underground sett > shoot > leaf, respectively) and the translocation factors were below 1, indicating low metal uptake. The results suggested that even though sugarcane waste-products insignificantly promote sugarcane growth, they can be used in agriculture due to the low metal accumulation in sugarcane and the reduction in metal bioavailability in the soil.

Short-term effects of sugarcane waste products from ethanol production plant as soil amendments on sugarcane growth and metal stabilization.

Numerous waste products have been widely studied and used as soil amendments and metal immobilizing agents. Waste utilization from ethanol production processes as soil amendments is one of the most promising and sustainable options to help utilize materials effectively, reduce waste disposal, and add value to byproducts. As a consequence, this present work carried out a four-month pot experiment of sugarcane (Saccharum officinarum L.) cultivation in Cd and Zn contaminated soil to determine the effect of three sugarcane waste products (boiler ash, filter cake and vinasse) as soil amendment on sugarcane growth, metal translocation and accumulation in sugarcane, and fractionation of Cd and Zn in soil by the BCR sequential extraction. Four treatments were tested: (1) non-amended soil; (2) 3% w/w boiler ash; (3) 3% w/w filter cake; and (4) a combination of 1.5% boiler ash and 1.5% vinasse (w/w). Our findings showed the improved biomass production of sugarcanes; 6 and 3-fold higher for the above ground parts (from 8.5 to 57.6 g per plant) and root (from 2.1 to 6.59 g per plant), respectively, as compared to non-amended soil. Although there was no significant difference in Cd and Zn uptake in sugarcane (mg kg(-1)) between the non-amended soil and the treated soils (0.44 to 0.52 mg Cd kg(-1) and 39.9 to 48.1 mg Zn kg(-1), respectively), the reduction of the most bioavailable Cd concentration (BCR1 + 2) in the treated soils (35.4-54.5%) and the transformation of metal into an insoluble fraction (BCR3) highlighted the beneficial effects of sugarcane waste-products in promoting the sugarcane growth and Cd stabilization in soil.