The following are responses and summaries of various readings related to Human Health, Disease, and the Environment.
Under the Weather: Temporal and Spatial Scaling
Though climate varies naturally over time, recent global warming is of great concern. The many parts of an area’s ecology such as soil fertility, species variability, and organic growth rates and reproductive cycles vary with changes in altitude and latitude; these differences are known as the spatial climate gradients. Too cold nights and winters and too warm days and summers have drastic impact on the populations and geographic range of disease carriers and can also have an effect on the organisms of disease as well. Climate variability taking place over the time frame from biyearly to every decade is due to atmospheric, oceanic, and cosmological influences, such as sunspots. These changes can result in multi-year droughts, monsoons lasting for decades, and vastly different hurricane activities, which have all been shown to affect productivity of plant life, likelihood of bird reproduction, and an increase in insect population. Longer time scales such as that of the little ice age can cause great population range shifts or possibly extinction. The recent global warming has resulted in earlier springs, declines in the populations of birds, mammals, and amphibians, and a change in geography for butterfly, bird, and marine invertebrates. While the average temperature has been increasing globally over the last century, of greater concern is the extreme temperature increases, higher in mid-day and lower in mid-night, which has been shown to have a greater impact on animal and plant species’ population and range. Recently experimental manipulation has been used in either localized outdoor environments or in laboratories to analyze what effects climate change could have on the ecosystem by altering the temperature of soil and air and type and amount precipitation or combination of the alterations: the growth rates of plants, invertebrate organism population, plant reproduction, and soil organism and chemical make-up have all been shown to be affected.
It may be possible through the analysis of how a disease vector reacts to changes in the environment, to predict what effect future climate change might have on that same vector. Climate change over long periods of time should not be used to predict possible ecological behavioral reactions because there are environmental factors in action other than climate. Many disease vectors are well adapted to scheduled environmental change such as seasonal cycles or ENSO. Also, socioeconomic changes are likely to be more significant over decades to centuries, rather than seasonally to annually. Only climate change experiment can provide the information necessary to prove causation because there may be other factors involved and the climate change is merely coincidental. Merely because an effect is seen only in a certain spatial area does not mean that it is caused by change in that particular region. Experiments are limited in size and therefore may not be able to predict what may result from similar climate change over a large area. These experiments need be focused on the diseases which are more dependent on climate change than not, such as dengue.
Health Perspective: How does agriculture influence human health?
Improved health and human nutrition is a key to putting an end to poverty. Though, if wealth is obtained without an improvement in diet, human health and nutrition will continue to decline. Poor nutrition and lack of nutritional options are, though not for a complete ignorance or neglect of the subject, still a major killer throughout the world, especially in the young and pregnant. The battle has begun to be fought on two fronts with many developing countries now also fighting against over nutrition and obesity. Obesity and malnutrition are together responsible for more than half of the world’s diseases, with nearly 100 million adults and 20 million children believed to be obese. Since the 1960s the staple foods such as cereals, pulses, and starchy roots have been phased out in many areas having been replaced by foods high in vegetable oils and sugars, especially in low income nations and the developing world. The decreased availability of staple foods in the developing countries seems to have gone hand-in-hand with the reduction of quality in human diets and nutrition. Agriculture and human health affect one another, though not necessarily equally. The processing which occurs during the production of food can greatly contribute to poor health, depending on how the food is being produced and consumed by the end user. Investigations need to be undertaken to find out what the policies initiated and enforced by agriculture which are causing these deficiencies are and look for alternative possible policies, perhaps to be policed by a sector other than agriculture itself.
Organic Agriculture and Human Health
Organic agriculture makes use of the natural ecological processes to produce food which is good without the negative effects. Organically grown food is better for use in seeking good human health and nutrition because it has greater nutritional quality and quantity, with much less chemical residue left over from pesticides, herbicides, and fertilizers. The produce which is grown organically gains nutrients from the soil in which it grows that would not be obtained by conventional means. Organic produce has a greater density of nutrients due to its decreased water content, have more iron, magnesium, vitamin C, and antioxidants, and have a balance of amino acids more in line with good human health. Organic livestock are healthier, less likely to contract a disease potentially harmful to themselves or humans, and have a lower ratio of saturated fat to unsaturated fat. Organic foods receive less processing than conventionally produced foods such as, chemicals, irradiation, additives, and flavors. Organically produced food does not contain nearly the residues which conventionally produced food does which can hurt the endocrine or immune system, cause cancer, and cause sexual reproductive problems even after being well cleaned. The antibiotics which are funneled in to conventional livestock to prevent disease and promote growth can create resistant strains in humans. Organic agriculture is better for the environment, the consumer, the government, the economy, and the industry. Going completely organic would likely result in an overall improved health of the population and a great reduction in the cost of human health.