Knowledge Drops

Knowledge at your finger tips!!!

20. July 2016 21:48
by D.V.CYRIL
0 Comments

The world of Chemicals

20. July 2016 21:48 by D.V.CYRIL | 0 Comments

 

 

Hai  friends 

Once again I am here.

Welcome to THE WORLD OF KNOWLEDGE

after a long gap due to technical glitches.

Chemicals are an integral part of everyday life.They play a role in every economic sector and nearly every industry, and many are critical to human well-being and sustainable development.Yet chemicals can also endanger human health and environment if not managed properly.Increasing amounts of hazardous waste is generated on a global scale.These wastes pose a serious risks to people and the environment.If it is not effectively controlled other non-hazardous waste and substances may also get contaminated. 

 CHEMICALS AND THE WORLD

Since 1970 the global chemical industry has grown in value from 171 billion dollar to 4 trillion dollar.It accounts for over 7% of global income and 9% of international trade.

ELEMENTS

About 115 elements are known.These chemicals singly or in combination make up all matter. 

Chemicals are an integral part of everyday life.

There are over 100,000 different substances in use today

  • Chemicals that assist to agricultural production,develop medicines,and produce consumer goods can be hazardous to human health over long term,accumulating in our bodies through environmental exposure.
  • In 2013 ,worldwide chemical sales were valued at 3.2 trillion euros.
  • Eliminate mercury,lead,cadmium;persistent organic pollutants,pesticides and industrial chemicals used in manufacturing.
  • CONSEQUENCES ARE DREADFUL
  • One million people die from occupational poisoning every year.
  • By 2020  developing countries will produce and use 31% to 33% of global chemicals respectively.
  • Chemical waste exacerbate climate change.
  • China has 25000 chemical enterprises producing and using 50,000 kinds of chemicals.Over 20 of them ranks among the greatest in the world.
  • Agricultural maximum residues are regulated for 2293 pesticides of 322 kinds.
  • Over 30 kinds of highly toxic pesticides,such as methamidophos,have been banned.
  • China has phased out 17 persistent organic pollutants.Cleaned up 20,000 tons of waste and polluted soil containing pesticide POPs as well as 13000 tons of waste and polluted soil containing polychlorinated biphenyles(PCBs).
  • Every minute, a person dies from exposure to toxic substances at work.Out of 160 million occupational illnesses per year,the bulk are caused by chemical agents.
  • In addition to the commercially available chemicals in the market(more than one lakh),over 1000 new chemicals enter the market every year.
  • Every day,we make myriad products out of chemicals - from buildings and clothing to machines and electronics.
  • High risk industries include mining,chemicals,construction,and textiles.Workers in sectors like transport and fishing are also facing risks.
  • New industries like microelectronics and nanotechnology have proven and potential risks.
  • Europe,Asia,North American Free Trade Area account for 93% of world chemical sales.
  • Exposure in services such as cleaning or hair dressing can be as lethal as in manufacturing or mining.Almost no sector is exempt.
  • Thousands of chemicals are carcinogenic,mutagenic and toxic to reproduction.Workers are exposed to such risks. 
  • Workers are exposed to carcinogens in production,where consumers are potentially exposed in usage and where recyclers face intolerable effects at the end of the chain.
  • More than 6,60,000 workers a year get occupational cancer.
  • In China pesticide use in rice systems had been estimated to cost 1.4 billion dollar per year in health expenses and effects of biodiversity.
  • In Burkina Faso , total cost of unsustainable chemical use and management was estimated at 24.2 million dollar per year in artisanal mining and 9.3 million dollar per year in the cotton sector; OVERALL COST OF ENVIRONMENTAL DEGRADATION AMOUNTED TO 18- 22 % OF ANNUAL GDP EQUIVALENT TO 1.7 BILLION DOLLAR.
  • WHO calculates that exposure to polluted water,soil, and air in 2012 resulted in an estimated 8.9 million deaths worldwide; largely in developing countries.
  • Sustainable Development Goals(SDG)targets ridding the planet of PCBs by 2028.
  • Every year health authorities identify an estimated 6,00,000 new cases of children with intellectual disabilities caused by childhood lead exposure.
  • Lead exposure accounts for 0.6 % of global burden of diseases.
  • A recent study estimates that reduced cognitive potentials(loss of IQ points)due to preventable childhood lead exposure equates to 98.2million points in Africa,283.6million in Asia,24.4 million in Latin America and the Caribbean,which translate into economic losses of 134.7,699.9 &142.3 billion dollars respectively.
  • In the first part of the twentieth century, a number of countries have restricted the use of lead paints.Despite those efforts , paints with high levels of lead are still widely available and used in countries for decorating  the interiors and exteriors of homes.
  • According to WHO more than 25% of global burden of human disease can be traced back to preventable environmental factors,including exposure to chemicals.

Common chemicals in hospitals range from

  • gluteraldehyde in disinfectants
  • Mercury in medical devices like IVs to formaldehyde in laboratories.
  • Dioxins in waste dumps.
  • Atmospheric chemistry is the crucial component that determines the atmospheric lifetimes of many species .Pollution that accumulates in the atmosphere influences the climate and the weather.
  • Polluting chemicals accumulate in the atmosphere and influence climate and weather.
  • Textile mills in Eastern Province(Zhejiang) consumes 42% of the world's textile chemicals.
  • 3500 chemical substances used to turn raw materials into textiles,10% of which are hazardous to human health or the environment.Many of these chemicals are persistent organic pollutants or hormone disruptors including nonyphenol,PFCs and phthalates.

POLLUTING INDUSTRIES IN INDIA

  • Tanneries are a cause of concern.2500 tanneries discharge about 24 million cubic meters of waste water containing high levels of dissolved solids and 400,000 tons of hazardous solid waste per year.
  • About 300 distilleries discharge 26 million kilolitres of spent wash per year containing many pollutants.
  • Thermal power plants discharge 100 million tons of fly ash which is expected to exceed 175 million soon.

Fly ash contains silicon,aluminium,iron and calcium oxides.This can cause silicosis,fibrosis of the lungs,cancer,and bronchitis.

  • One-sixth of total pesticides used in India are those banned in other countries.
  • 50% of the pesticides used in India are for cotton.
  • According to Ministry of Environment and Forests 7.2 million tons of hazardous waste is generated in India annually.
  • Paper consumption has increased by about 40% after introduction of computers and e-mail.
  • Most of the ships sent to the yards contain hazardous material such as asbestos,toxic paints,and fuel residues.
  • Modern agriculture and sanitation depend heavily on pesticides.WHO estimates that every year there are 3 million cases of pesticide poisoning worldwide,which results in over 250,000 deaths.

ACCORDING TO WORLD HEALTH ORGANISATION

  • 240 thousands die annually due to acute poisonings of chemicals.
  • 186 thousand die from self poisonings from pesticides.
  • 4.9 million deaths were attributed to exposure to chemicals in 2004.
  • 2 million die annually due to indoor smoke from solid fuel use.
  • 1.2 million die from outdoor air pollution.
  • 375 thousands die from outdoor air pollution.

CHEMICAL COMPOSITION OF ATMOSPHERIC AIR

  • Nitrogen  78%
  • Oxygen 21%
  • Carbon dioxide less than 1 %.

POLLUTANT CHEMICALS

  • Carbon dioxide,nitrogen oxides, sulphur dioxide, ground level ozone,and radio active substances and particulate matter.
  • WHO calculates that exposure to polluted soil,water and air in 2012 resulted in an estimated 8.9 million deaths worldwide, largely in developing countries.
  • Oxides of carbon and nitrogen and sulphur dioxide.
  • Hydrocarbons like methane and benzene.

 Every year , health authorities identify an estimated 600,000 new cases of children with intellectual disabilities caused by childhood lead exposure.

Lead,asbestos,sulphuric acid droplets and soot are particulate matter that pollutes atmosphere.

Sulphur trioxide formed when sulphur dioxide reacts with oxygen.Sulphur trioxide combines with water to form sulphuric acid.

Dichloro- diphenol- trichloroethane(DDT)  is an insecticide recognised as a dangerous pollutant and suspected carcinogen

DIOXINS

Dioxins are chemical compounds highly toxic to humans and animals.It is also carcinogenic.Dioxins are formed during the incomplete incineration of waste and burning of plastics,coal or cigarettes.When fuel is partly burnt in a vehicle, dioxins are released. These dioxins are deposited on plants, soil, and water and thereby enter the food chain.

Endosulfan belong to a group of Persistent Organic Pollutants(POPs).

MERCURY

Mercury is a liquid metal that is dangerous to humans and animals.Small doses can cause headache.Large amounts could lead to death.Mercury if inhaled,swallowed, or absorbed through the skin  can damage the nervous system in humans.It accumulates in the body and is  not excretable.Chemical industries and plastic manufacturing use large amounts of mercury and release it with the effluents into rivers,lakes,and seas or dump it on land as waste.This has led to poisoning of fish and humans.

POPs

POPs remain in the environment for long,travel far,accumulate in the body,and are not easily detectable.

  • PCBs are very stable chemical compounds that have good insulation qualities,are fire resistant, and have low electrical conductivity.Widely used in capacitors, transformers, hydraulic systems,fluorescent lamps etc.
  • PCBs are extremely toxic.And they can cause cancer in animals and liver and nervous disorders in humans.
  • When burnt , they leave a toxic ash and when buried,they leach into ground water.Rainfall deposits PCBs in the atmosphere into rivers and seas.

LEAD

Lead is an extremely poisonous metal that accumulates in organisms.Large doses can cause paralysis, blindness, and even death in humans.Even a small amount of lead in a pregnant woman could affect the mental development of the child.Lead in the atmosphere contaminates leafy vegetables and fruits.Most of the lead we breath in comes from vehicle exhausts.Lead is added to petrol to prevent knocking of the engine.Lead is also found in batteries,paints,bullets,and some alloys.

CFCs   and OZONE LAYER

Ozone is made up of molecules containing 3 oxygen atoms.This extremely rare gas exists in the upper atmosphere or stratosphere, between 10 and 50 kilometer above the earth.Ozone absorbs most of the harmful UV-B radiation from the sun.It also screens out the deadly UV-C radiation.Depletion of Ozone layer has several harmful effects on humans and ecosystems.Montreal Protocol on Substances that Deplete the Ozone layer was adopted in September 1987. 

A single atom of chlorine can destroy 1,00,000 molecules of Ozone.

DDT

Dichloro-diphenyl-trichloroethane or DDT is an insecticide introduced first in the US in the 1940s and later in many parts of the world to protect crops from insects.It played an important role in green revolution.It is highly toxic to vertebrate mammals and some species of fish and birds.DDT was banned in the US in 1973.It was late Rachel Carson's Silent Spring that brought the lethal effects of DDT. 

Volatile Organic Compounds(VOC)

Exhaust emissions from auto- vehicles includes carbon monoxide,hydrocarbons,suphur dioxide,and VOCs.Crbon monoxide and Nitrogen oxide and dioxide are extremely poisonous.

FERTILIZERS

 Nitrogen,Phosphorus, and Potassium are the three main chemicals added to the soil .These chemicals end up in drinking water sources and other water bodies causing pollution.

                                                                      ELEMENTS 

Elements are the  basic chemical building blocks of matter,and atoms are the basic unit of an element.We can make anything by combining atoms together on earth.Ranging from the smallest beetle to the tallest sky scraper are  different combinations of elements.

Elements are different substances like solids,liquids and gases, made from atoms that have different inner structures.If two atoms have same number of protons, they are atoms of the same element.An atom is the smallest unit of an element.

 Under everyday conditions, two of the elements - mercury and bromine - are liquids, 11 are gases, and the rest are solids.

  • You could build living things from a handful of elements based on carbon, and you could make the water that covers most of our planet from just two elements - hydrogen and oxygen.
  • To make everything on earth we need about 100 elements in total.
  • Most of the naturally occurring elements are locked in rocks or drifting around in the atmosphere
  • Elements are made from protons,neutrons and electrons glued together by strong forces
  • It is possible to build brand new ones.Scientists have done it in laboratories pushing the total number of elements to 118.
  • 96% of human body is made of just 4 elements  -  OXYGEN,CARBON,HYDROGEN AND NITROGEN.

 THE PERIODIC TABLE

Elements are sorted into a grid according to their atomic structure,in patterns.Elements that behave in similar ways group together,so we can predict how an element will behave from its place in the grid.The Periodic Table was created by a Russian chemist,Dmitri  Mendeleev in 1869.

  • The Periodic  Table is made up of rows called periods and columns called group.As we move across each period, the elements change from solid metals (on the left) to gases (on the right).
  • The elements in a period all have the same number of electron shells.
  • Elements in groups are similar because they have the same number of electrons in their outer shell.
  • Within the table are bigger blocks of elements that behave in similar ways.
  • On the left are reactive metals such as sodium(Na).
  • Everyday metals occur in the middle of the table in a set called the transition metals.
  • Non - metals are mostly on the right of the table.
  • Rare earth metals are all soft metals. 
  • Under everyday conditions, two of the elements - mercury and bromine - are liquids, 11 are gases, and the rest are solids.
  • Atoms get bigger and heavier as we move down each column(group) of the table.This is because there are more protons in the nucleus and more electrons in the shells(rings) around it.
  • A shell is added each time we move another step down a group.
  • Atomic number is the number of protons inside the nucleus of the atom.
  • The metal Titanium has 22 protons.Atomic number is 22.
  • The total number of protons and neutrons in one atom of Titanium is 47867.This is the atomic mass.
  • The name of an element often describes it's properties.Titanium is named after Titans,  ancient Greek Gods of incredible strength.
  • Ti is the chemical symbol for Titanium.This is the shortest way of representing an element.
  • Carbon is the 4th most common element.Plants and animals are made of 18% carbon.
  • Helium makes up a quarter of the entire mass of the Universe.
  • Platinum(Pt) is one of the most expensive elements.A man - sized mass of platinum would cost about 3 million pounds.
  • A tennis ball size of Plutonium will weigh 2 kilograms.It is one of the heaviest natural elements.
  • The most recently discovered element, ununseptium(Uus),was created in a laboratory in 2010.
  • A tennis ball  size made of Plutonium (Pu) will weigh 2 kilogram.It is one of the heaviest natural elements.
  • CHEMICAL REACTION
  • In a chemical reaction,one ingredient(called a reactant)combines with a second one.During the reaction,the bonds that hold together the atoms or molecules of the reactants split apart.The atoms then rearrange themselves and new bonds form between them to make a different set of chemicals called the product.
  • Nearly 40 % of the world's Oxygen is produced in the tropical Rainforests.
  • Atoms and molecules are constantly rearranging themselves  - breaking down old things and building up new ones.Chemistry helps to explain how this happens through step- by -step changes called chemical reactions.
  • In a reaction, elements join together to make bigger units called compounds, or compounds split back into their original elements.Many reactions are silent and invisible.Others like an exploding firework,are energetic and violent.Reactions are the amazing transformations that drive many of the things around us.
  • When candles flicker and cakes rise in your oven,reactions are rearranging atoms into new and different forms.
  • Most chemical reactions need to be kick - started using activation energy. 

CRUDE OIL

Crude oil is composed of 

  • Hydrocarbons 13% by weight.
  • Carbon 85%
  • Nitrogen 0.5%
  • Sulphur 0.5%
  • Oxygen 1%

Scientists have found  chemicals used to treat cancer and HIV in reef creatures.

There are still many compounds that prove valuable to medicine.

The way molecules are organised in the hydrocarbon is a result of the original composition of algae,plants,or plankton from millions of years ago.The amount of heat and pressure the plants were exposed to also contributes to variations that are found in hydrocarbons and crude oil.

  • Around 100,000 different chemical substances find their way into everyday products.
  • In 2004 4.9 million deaths were attributable to exposure to chemicals.
  • 240 thousands died from chemical acute poisonings.
  • 186 thousands die from self poisonings from pesticides.

According to WHO

More than 25%of global burden of human disease can be traced back to preventable environmental factors,including exposure to chemicals.