title: Studies of Leaching of Metals from Food Ceramics

authors: Velayudhan, Prajusha Veethampulli

abstract: In this study the leaching potential of food ceramic wares available in New Zealand has been done using ICP-MS analysis. A survey of ceramic wares purchased in New Zealand markets ranging from historical (antique) Victorian eras (Wilemen bone china and Chapman), mid - 20th century (Alfred Meakin), 1960-1980’s New Zealand-made (Crown Lynn) and modern day ceramic wares manufactured in China, India and Thailand was carried out with respect to their elemental compositions, ceramic composition and leaching potential. All these ceramic wares were found to contain various amounts of heavy metals in their glazes used for imparting special colours, texture and smooth finishes.  
Structural characterisation of these ceramic wares was carried out using different techniques such as solid state magic angle spinning NMR, Fourier transform infrared (FTIR), scanning electron microscopy (SEM) coupled to energy dispersive X-ray analysis (EDX), and X-ray fluorescence (XRF) to determine which elements were present in the bulk of ceramics clay sourced-body and in the glazes. The results of the XRF analysis informed the inductively coupled plasma mass spectroscopy (ICP-MS) studies by providing a list of elements to follow. In general XRF identified a number of heavy metals of interest in all the ceramic wares such as lead and cadmium in Victorian era Wileman and Chapman, mid-20th century Alfred Meakin and especially in the Crown Lynn wares. Barium was predominantly the heavy metal of interest in all modern ceramic wares that are predominantly used by many people in New Zealand. Cobalt, chromium, tin and zinc were present in all the ceramic wares. However, cadmium was significantly present in  the red coloured modern ceramic wares.
These ceramic wares were subjected to leaching tests to detect whether various elements of relevance such as lead, cadmium, barium, cobalt and chromium migrated to any great extent into liquids exposed to these ceramic wares. Leaching studies were done following the ASTM 738 -94 standard test methods for specific metals leaching into 4% acetic acid solutions after a 24 hour exposure time. The lead leached from Victorian era Wileman bone chinaware studied with 4% acetic acid leaching solution was found to exceed the standard safe limits of lead as given by  the FDA (3 µg/mL) and European Council Directive 84/500/EC (4mg/L). The Victorian era Chapman and the New Zealand made Crown Lynn ceramic wares leached lead with 4% acetic acid leaching solution but was below the standard safe limit. However, the modern day ceramic wares manufactured in China, India and Thailand analysed in this research were found to leach extremely low levels of barium being well below the oral reference dose (RFD) for barium given by the US Environmental protection agency (EPA) as 0.07 mg/kg/day, i.e. 4 mg/person/day.
Ceramic teacups were exposed to other leachate solutions based on the normal domestic use and all the leachate solutions were analysed with ICP-MS. These leachate solutions which were exposed to the ceramic teacups for a ten minutes leaching test included: orange juice at room temperature, hot tea at 80 - 95 oC, hot water at 80 - 95 o C, cold water at 4 oC and Coca Cola at room temperature in which some of the Crown Lynn teacups studied were found to be continuously leaching lead in all the tested solutions at varying conditions i.e. pH of the leaching solutions, its temperature and duration of exposure to the leaching solution have influence in migrating the metals from these ceramic teacups tested. However, the level of lead leached from these ceramic teacups was well below the standard safe limits of lead leached from ceramic wares.

text: Studies of Leaching of Metals from Food Ceramics In this study the leaching potential of food ceramic wares available in New Zealand has been done using ICP-MS analysis. A survey of ceramic wares purchased in New Zealand markets ranging from historical (antique) Victorian eras (Wilemen bone china and Chapman), mid - 20th century (Alfred Meakin), 1960-1980’s New Zealand-made (Crown Lynn) and modern day ceramic wares manufactured in China, India and Thailand was carried out with respect to their elemental compositions, ceramic composition and leaching potential. All these ceramic wares were found to contain various amounts of heavy metals in their glazes used for imparting special colours, texture and smooth finishes.  
Structural characterisation of these ceramic wares was carried out using different techniques such as solid state magic angle spinning NMR, Fourier transform infrared (FTIR), scanning electron microscopy (SEM) coupled to energy dispersive X-ray analysis (EDX), and X-ray fluorescence (XRF) to determine which elements were present in the bulk of ceramics clay sourced-body and in the glazes. The results of the XRF analysis informed the inductively coupled plasma mass spectroscopy (ICP-MS) studies by providing a list of elements to follow. In general XRF identified a number of heavy metals of interest in all the ceramic wares such as lead and cadmium in Victorian era Wileman and Chapman, mid-20th century Alfred Meakin and especially in the Crown Lynn wares. Barium was predominantly the heavy metal of interest in all modern ceramic wares that are predominantly used by many people in New Zealand. Cobalt, chromium, tin and zinc were present in all the ceramic wares. However, cadmium was significantly present in  the red coloured modern ceramic wares.
These ceramic wares were subjected to leaching tests to detect whether various elements of relevance such as lead, cadmium, barium, cobalt and chromium migrated to any great extent into liquids exposed to these ceramic wares. Leaching studies were done following the ASTM 738 -94 standard test methods for specific metals leaching into 4% acetic acid solutions after a 24 hour exposure time. The lead leached from Victorian era Wileman bone chinaware studied with 4% acetic acid leaching solution was found to exceed the standard safe limits of lead as given by  the FDA (3 µg/mL) and European Council Directive 84/500/EC (4mg/L). The Victorian era Chapman and the New Zealand made Crown Lynn ceramic wares leached lead with 4% acetic acid leaching solution but was below the standard safe limit. However, the modern day ceramic wares manufactured in China, India and Thailand analysed in this research were found to leach extremely low levels of barium being well below the oral reference dose (RFD) for barium given by the US Environmental protection agency (EPA) as 0.07 mg/kg/day, i.e. 4 mg/person/day.
Ceramic teacups were exposed to other leachate solutions based on the normal domestic use and all the leachate solutions were analysed with ICP-MS. These leachate solutions which were exposed to the ceramic teacups for a ten minutes leaching test included: orange juice at room temperature, hot tea at 80 - 95 oC, hot water at 80 - 95 o C, cold water at 4 oC and Coca Cola at room temperature in which some of the Crown Lynn teacups studied were found to be continuously leaching lead in all the tested solutions at varying conditions i.e. pH of the leaching solutions, its temperature and duration of exposure to the leaching solution have influence in migrating the metals from these ceramic teacups tested. However, the level of lead leached from these ceramic teacups was well below the standard safe limits of lead leached from ceramic wares.

year: 2013

title: Conceptual review article

authors: O’Driscoll, Michael P.

subjects: stress

abstract: The article which follows is the second in our series of ‘conceptual’ reviews, which provide a forum for leading researchers of stress and well-being to present an overview and critique of a specifi ed area of stressrelated research. The overarching goals of this section of the journal are to (a) review extant theories and research on stress and health, (b) offer an opportunity for new conceptual frameworks to be articulated and critiqued and (c) develop and promote theoretical frameworks associated with stress, health, coping and well-being.

text: Conceptual review article The article which follows is the second in our series of ‘conceptual’ reviews, which provide a forum for leading researchers of stress and well-being to present an overview and critique of a specifi ed area of stressrelated research. The overarching goals of this section of the journal are to (a) review extant theories and research on stress and health, (b) offer an opportunity for new conceptual frameworks to be articulated and critiqued and (c) develop and promote theoretical frameworks associated with stress, health, coping and well-being.

year: 2011

title: An investigation into the commercial feasibility of Jasus edwardsii aquaculture in New Zealand

authors: Ruru, Ian Hector

subjects: New Zealand

abstract: In 1996 New Zealand introduced legislation to allow Jasus edwardsii pueruli to be collected as "seedstock" and ongrown in a commercial aquaculture trial. The aim of this thesis was to investigate the commercial feasibility of J. edwardsii aquaculture in New Zealand by working with an organisation involved in the trial.
The methodology involved a combination of experiments in the field, in laboratories, and within an ongrowing facility. This thesis examined five key areas and found the following:
1. Data obtained in the research indicates that New Zealand will continue to rely on harvesting pueruli from the wild since significant technical obstacles remain in the development of commercial scale pueruli hatcheries. Forecast data, obtained using the delphi technique and information about current research on larval rearing, indicates that commercial scale supply of pueruli from hatcheries may occur between 2017 and 2021.
2. Harvesting trials collected a low number of pueruli with the lowest unit cost for collection being $1.80. A greater collection rate could be achieved with a better understanding of seasonal and local settlement patterns.
3. Survival rates in pueruli transporting experiments were significantly affected by stocking density, time and temperature. The safest transit conditions were achieved with 15 pueruli per litre for less than 6 hours at 14°C.
4. A range of stocking densities, from 3 lobsters per tank to 12 per tank, were tested for their effect on growth of six-month old lobsters. The lobsters were reared in a total recirculation seawater system at a constant 16°C, and fed fresh mussels (Perna canaliculus). For the 121 day trial, no statistically significant effect was detected. However, there was a trend for growth rates to be highest at 3 and 6 lobsters per tank and for growth rates at stocking densities of 9 and 12 lobsters per tank to decrease after Day 50. Lobsters showed increased mortality at the highest stocking rate.
5. A bioeconomic model of a hypothetical farm was developed to assess economic benefits and risks and to determine overall profitability. The model showed an annual net cash position of $287,100 and cumulative cash position of $859,200 by the 10th year of operation based on annual sales of 10,837 kg at $65 per kg. The model indicates that the highest cost components in the first 10 years are processing and transport, and labour. Based on the model and the scenarios examined, profitability is very sensitive to factors such as the farm size, processing and transport costs, and sale price. Biological factors such as growth rates, survival, and feed requirements also influence overall profitability. Good returns will depend upon consistent exports of high quality lobsters.
The study concludes that commercial feasibility will be affected by these key areas. The potential of J. edwardsii aquaculture in New Zealand will continue to benefit from further research.

text: An investigation into the commercial feasibility of Jasus edwardsii aquaculture in New Zealand In 1996 New Zealand introduced legislation to allow Jasus edwardsii pueruli to be collected as "seedstock" and ongrown in a commercial aquaculture trial. The aim of this thesis was to investigate the commercial feasibility of J. edwardsii aquaculture in New Zealand by working with an organisation involved in the trial.
The methodology involved a combination of experiments in the field, in laboratories, and within an ongrowing facility. This thesis examined five key areas and found the following:
1. Data obtained in the research indicates that New Zealand will continue to rely on harvesting pueruli from the wild since significant technical obstacles remain in the development of commercial scale pueruli hatcheries. Forecast data, obtained using the delphi technique and information about current research on larval rearing, indicates that commercial scale supply of pueruli from hatcheries may occur between 2017 and 2021.
2. Harvesting trials collected a low number of pueruli with the lowest unit cost for collection being $1.80. A greater collection rate could be achieved with a better understanding of seasonal and local settlement patterns.
3. Survival rates in pueruli transporting experiments were significantly affected by stocking density, time and temperature. The safest transit conditions were achieved with 15 pueruli per litre for less than 6 hours at 14°C.
4. A range of stocking densities, from 3 lobsters per tank to 12 per tank, were tested for their effect on growth of six-month old lobsters. The lobsters were reared in a total recirculation seawater system at a constant 16°C, and fed fresh mussels (Perna canaliculus). For the 121 day trial, no statistically significant effect was detected. However, there was a trend for growth rates to be highest at 3 and 6 lobsters per tank and for growth rates at stocking densities of 9 and 12 lobsters per tank to decrease after Day 50. Lobsters showed increased mortality at the highest stocking rate.
5. A bioeconomic model of a hypothetical farm was developed to assess economic benefits and risks and to determine overall profitability. The model showed an annual net cash position of $287,100 and cumulative cash position of $859,200 by the 10th year of operation based on annual sales of 10,837 kg at $65 per kg. The model indicates that the highest cost components in the first 10 years are processing and transport, and labour. Based on the model and the scenarios examined, profitability is very sensitive to factors such as the farm size, processing and transport costs, and sale price. Biological factors such as growth rates, survival, and feed requirements also influence overall profitability. Good returns will depend upon consistent exports of high quality lobsters.
The study concludes that commercial feasibility will be affected by these key areas. The potential of J. edwardsii aquaculture in New Zealand will continue to benefit from further research.

year: 2000