Properties of DDT

Introduction

Dichlorodiphenyltrichloroethane or DDT was first synthesised by Othmar Zeidler, an Austrian chemist in 1874. Paul Hermann Müller, a Swiss chemist discovered the insecticidal properties of DDTs in 1939. During World War II, it was used to prevent the spread of malaria, typhus and other insect-borne diseases among non-combatants and troops. It was also used to control the insect in crop and livestock production, homes, institutions, and gardens.

What Is DDT?

Dichlorodiphenyltrichloroethane or DDT is a chemical compound and the formula is $\mathrm{C_{14}H_{9}Cl_{5}}$. It is also called 1,1,1-trichloro-2,2-bis(p-chlorophenyl) ethane. Under standard temperature and pressure (STP), pure DDT exists as a tasteless and colourless or white crystalline solid that started to melt at 108.5 °C (227.3 F).

Spraying DDT to protect against bothersome insects

DDT belongs to the organochlorine family which has a strong capability to kill insects. After chlorobenzene $\mathrm{(C_{6}H_{5}Cl)}$ reacts with a sulphuric acid as catalyst $\mathrm{(H_{2}SO_{4})}$, it naturally forms Chloral $\mathrm{(CCl_{3}CHO)}$.

Properties of DDT

• The entire form of DDT is dichlorodiphenyltrichloroethane and its molecular formula is $\mathrm{C_{14}H_{9}Cl_{5}}$.

• The IUPAC name of DDT is 1,1,1-Trichloro-2,2-bis(4-chlorophenyl) ethane.

• It is found in colourless or white crystal powder form and it is tasteless.

• The molar mass of DDT is 354.48 grams per mole.

• Under standard temperature and pressure (STP), the chemical compound has a density of 0.98 to 0.99 gram per centimetre cube.

Figure 2 − Structure of DDT

• The melting point of this chemical compound is 108.5 °C or 381.6 Kelvin.

• The boiling point of this chemical compound is 260 °C or 533.15 Kelvin. But when DDT is heated with this temperature, it decomposes completely.

• It has poor water solubility. DDT solubility in water is 25 micrograms per litre at a temperature of 25°C.

• Dichlorodiphenyltrichloroethane is soluble in acetone and Ethyl ether.

Uses of DDT

In insects, dichlorodiphenyltrichloroethane or DDT opens the sodium ion channel in the neurons, which spontaneously makes them to kill. For this reason, the insects experience spasms and then die. But due to the negative effect of DDT on nature and human health, many countries banned the use of this chemical compound.

• It is widely used throughout the world to eradicate the insects which are responsible for diseases like typhoid, malaria, yellow fever, etc.

• DDT was the main component of malaria removal in Italy and the United States. During 1943-44, it was commonly used to control the epidemic of typhoid in Italy and Germany.

• It was vividly used in the agricultural industry from 1950 to 1980 as an insecticide.

• It was also used by farmers to enhance and protect their crops from the insects and pests.

Effects of DDT on Health

DDT is also known as organic pollutant. This chemical compound can easily penetrate the soil and stays there for upto 30 years. DDT does not dissolve in water because it is made synthetically and it manages its way to the food chain.

• The chemical compound is an endocrine disruptor. If anyone is exposed to this chemical compound, then it interferes with the endocrine system.

• In many studies, it shows that DDT is toxic. It is suspected to be carcinogenic for humans too.

• In the US National Toxicology Program (NTP) this compound is listed as moderately dangerous and in the World Health Organization (WHO) as moderately hazardous, depending upon a rat oral LD50 of 113 mg per kg. It is believed that DDT is non-toxic for humans by indirect exposure.

• In case of pregnant woman, if they came to contact indirectly with DDT by a person who is exposed to DDT, is more likely to have an unplanned abortion.

• According to some studies, DDT interferes with the function of the thyroid in pregnant women.

• According to the other reports, pregnant women who have DDT in their blood more than the normal level are more likely to give birth to an autism child.

• In some studies, on liver cancer it shows that this compound can increase the risk of hepatocellular carcinoma.

Conclusion

Dichlorodiphenyltrichloroethane or DDT is a synthesized chemical compound used as insecticide and pesticide. After World War II, it was used vividly in agriculture and combat against the insect-borne disease.

Its health hazards in human, complexes arise in animals and environmental pollution by depositing in the soil for 30 years, the use of DDT was completely banned by the countries. Because of its chemical properties, it accumulates in animals. In the food chain the lower- level animals are eaten by the higher-level animals.

FAQs

1. What is the boiling point of the DDT?

The boiling point of this chemical compound is roughly 260°C or 533.15 K.

2. What are the physical properties of DDT?

DDT is found as colourless or white crystal powder form and it is tasteless and almost odourless. The molar mass of DDT is 354.48 grams per mole. Under standard temperature and pressure (STP), the chemical compound has a density of 0.98 to 0.99 gram per centimetre cube. The melting point of this chemical compound is roughly 108.5 °C or 381.6 K.

3. What are the consequences of DDT in the environment?

DDT has devastating effects on the marine ecosystem. Due to poor solubility, it has a high level of bioaccumulation in water leads to major hazards in marine life for a long time. DDT is also toxic for fish.