Systematic Review of Potential Health Risks Posed by Pharmaceutical, Occupational and Consumer Exposures to Metallic and Nanoscale Aluminum, Aluminum Oxides, Aluminum Hydroxide and Its Soluble Salts

Aluminum (Al) is a ubiquitous substance encountered both naturally (as the third most abundant element) and intentionally (used in water, foods, pharmaceuticals, and vaccines); it is also present in ambient and occupational airborne particulates. Existing data underscore the importance of Al physical and chemical forms in relation to its uptake, accumulation, and systemic bioavailability. The present review represents a systematic examination of the peer-reviewed literature on the adverse health effects of Al materials published since a previous critical evaluation compiled by Krewski et al. (2007). Challenges encountered in carrying out the present review reflected the experimental use of different physical and chemical Al forms, different routes of administration, and different target organs in relation to the magnitude, frequency, and duration of exposure. Wide variations in diet can result in Al intakes that are often higher than the World Health Organization provisional tolerable weekly intake (PTWI), which is based on studies with Al citrate. Comparing daily dietary Al exposures on the basis of “total Al”assumes that gastrointestinal bioavailability for all dietary Al forms is equivalent to that for Al citrate, an approach that requires validation. Current occupational exposure limits (OELs) for identical Al substances vary as much as 15-fold. The toxicity of different Al forms depends in large measure on their physical behavior and relative solubility in water. The toxicity of soluble Al forms depends upon the delivered dose of Al+ 3 to target tissues. Trivalent Al reacts with water to produce bidentate superoxide coordination spheres [Al(O2)(H2O4)+ 2 and Al(H2O)6 + 3] that after complexation with O2•−, generate Al superoxides [Al(O2•)](H2O5)]+ 2. Semireduced AlO2• radicals deplete mitochondrial Fe and promote generation of H2O2, O2 • − and OH•. Thus, it is the Al+ 3-induced formation of oxygen radicals that accounts for the oxidative damage that leads to intrinsic apoptosis. In contrast, the toxicity of the insoluble Al oxides depends primarily on their behavior as particulates. Aluminum has been held responsible for human morbidity and mortality, but there is no consistent and convincing evidence to associate the Al found in food and drinking water at the doses and chemical forms presently consumed by people living in North America and Western Europe with increased risk for Alzheimer\u27s disease (AD). Neither is there clear evidence to show use of Al-containing underarm antiperspirants or cosmetics increases the risk of AD or breast cancer. Metallic Al, its oxides, and common Al salts have not been shown to be either genotoxic or carcinogenic. Aluminum exposures during neonatal and pediatric parenteral nutrition (PN) can impair bone mineralization and delay neurological development. Adverse effects to vaccines with Al adjuvants have occurred; however, recent controlled trials found that the immunologic response to certain vaccines with Al adjuvants was no greater, and in some cases less than, that after identical vaccination without Al adjuvants. The scientific literature on the adverse health effects of Al is extensive. Health risk assessments for Al must take into account individual co-factors (e.g., age, renal function, diet, gastric pH). Conclusions from the current review point to the need for refinement of the PTWI, reduction of Al contamination in PN solutions, justification for routine addition of Al to vaccines, and harmonization of OELs for Al substances

Energy requirement of ISA ESSOR Guinea fowl (Numida meleagris) as a meat bird in a hot savanna climate

No Abstract Available Ghana Jnl agric. Sci, Vol.36 2003: 65-6

Reproductive and milking performance of a herd of Friesian W N'Dama cattle

Production records of a herd of Friesian W N'Dama cattle reared on-station were examined to assess their potential for use as dairy animals in the tropics. In addition, the radio- immunoassay technique was used to measure plasma progesterone concentrations to determine the attainment of puberty and resumption of ovarian activity postpartum in heifers and cows, respectively. A Friesian bull was always used to serve females on heat. Bull calves were significantly (P< 0.05) heavier at birth than heifer calves; the respective mean (1SE) weights being 3011 kg and 2711kg. The season of birth also significantly affected birth weight with calves born in the wet season being heavier than their dry season born counterparts (wet = 3111 kg; dry = 2611 kg;

Characterization of peri-urban dairy production system in Ghana. 1. Social attributes and characteristics of the production environmen

A survey was carried out in five districts on the Accra plains to characterize the peri-urban dairy system. Results of the survey indicated that about half of the farms visited had hired herd managers who were paid in kind with milk. The Fulani ethnic group constituted 58.2 per cent of the herdsmen encountered, followed by Ga, 20.9 per cent, Ewe, 12.0 per cent, and other mixed group, 8.9 per cent. The educational level of household heads was generally low; 49.1 per cent were illiterate, 22.0 per cent had Arabic education, while 18.0 and 10.9 per cent had primary and secondary education, respectively. Utility services, namely electricity, water and telephone, were non-existent. There were little or no farm equipment and most farmers used hand dipping as a means of applying acaricide. Integration of crops and livestock production was very low. Tenancy was communal with no private grazing lands. It was concluded that the factors mentioned above were constraints to smallholder peri-urban dairy production and need to be addressed. Ghana Jnl agric. Sci. Vol.30(2) 1997: 87-9

A survey on live- stock and milk production characteristics of peri-urban agropastoral dairying in Ghana

A survey was conducted in five districts on the Accra plains to characterize the peri-urban dairy system. Results from the survey indicated that sale of milk (fresh or processed) by farmers as well as the amount marketed varied according to districts. A high percentage of farmers in Ga Rural (82.4 per cent), Tema (85.7 per cent), and Ewutu-Effutu-Senya (91 percent) districts which are close to marketing centres mainly sold fresh milk, while farmers in the North Tongu and Dangbe West districts farther away from marketing centres mainly sold processed milk, 76.2 and 66.7 per cent, respectively. Consumption of processed milk by farmers in the various districts was significantly (

Characterization of peri-urban dairy production in Ghana. 2. Health and other Constraints in the production system

A survey was carried out in five districts of the Accra plains to characterize the peri-urban dairy system. Results of the survey indicated that farmers were not treating their animals with anthelmintic. The use of acaricide and the control of trypanosomiasis was fairly frequent. Skin diseases, ticks, digestive diseases, and trypanosomiasis were the most important diseases affecting farmers' cattle in that order. The lack of livestock extension and the unwillingness of banks to provide credit facilities for cattle farming were identified as other factors hampering the growth of the dairy industry in Ghana. Ghana Jnl.agric. Sci Vol.31(2), 1998: 197-20

A survey on processing and marketing characteristics of peri-urban agropastoral Dairying in Ghana

A survey was conducted in five districts on the Accra plains to characterize the peri-urban dairy production system. Results from the survey indicated that farmers were keeping cattle, sheep, goats, and poultry (Guinea fowl, turkey, chicken, and duck), cattle being the only species milked. The mean flock size was 73.6 TLU with a coefficient of variation of 103 per cent. The average cattle herd size was 133. Farmers made limited use of agro-industrial by-products. Cultivation of pastures, improved fodder, and multipurpose trees was non-existent, and neither was any system of cut and carry practised. The use of concentrate and protein supplementation was also negligible. The mean length of the dry season was 5.2 1 0.7 months. Offtake was low at 8.9 per cent per annum. Replacement and calving rates were 0.7 and 0.67, respectively. The mean age at first calving and calving interval were 36 and 14.4 months, respectively. The mean lactation length was 8.5 months. There were no crossbreds of the type 'exotic W local'. The Sanga was the predominant breed of cattle and constituted over 76 per cent of cattle kept on the Accra plains. Feeding of calves was by suckling residual milk from dams after partial milking. Calves were allowed to suckle until the cow was nearly dry, leading to a long mean calf weaning age of 8.4 months. Cows were milked once daily usually in the mornings. The mean daily partial milk yield per cow was 1.55 1 0.22 l. Mean partial annual milk yield per farm was 10,040 1 2952 l. It was concluded that the system required substantial transfer of improved technologies to increase milk production. Ghana Jnl.agric. Sci Vol.32(1), 1999: 53-5

The effect of farm (herd) and season of calving on the reproductive performance of Sanga cows in smallholder peri-urban dairy farms in the Accra plains

No Abstract. Ghana Journal of Agricultural Science No. 1, 2005: 37-4