Wani is an umbrella bearer.

She works in the largest market in Thailand, right across the Cambodian border near the town of Poipet. Ten years ago, this was a small village of only 7,000 people.

Now, it has a population of 84,000 and seven casinos catering to Thailand's rich. Former refugees, landless peasants and the unemployed flock to Poipet to find jobs. But there are simply not enough to go around.

Most residents eke out an existence in the huge market on the border. Some jobs are plain, like those for unskilled workers, or venders, but some are unique, like pulling the wings off edible grasshoppers.

Wani, 12, uses her umbrella to shade Thai clients walking the short distance between the border to the casinos, earning an average of 30 baht a day, or about 90 yen.

Child labor is taken for granted in this dirt-poor town, with children the major source of income for many families.

Desperate parents sell their children as a last resort. The victims are taken to Thailand to work as flower and candy vendors, farm hands, laborers on construction sites, domestic helpers, beggars or sex workers.

In extreme cases, babies are trafficked for their organs or put up for adoption. More than 1 million children are believed to be victims. In the town of Poipet alone, more than 3,000 children were picked up and sent back over the border last year -- countless others are simply lost.

As the ambassador of the Japan Committee for UNICEF, I joined a mission in August to learn more about the situation.

Wani lives with her parents. She has never gone to school, never has a bath and has never worn shoes in her life.

I went to her home on the rainy day I met her. She lives more than 4 km from the border, making the daily trip by bike taxi. Waking at 5 a.m., she reaches the border before it opens at 7 a.m. Crossing is easy; adults pay 10 baht but children go for free. No identification is needed.

She works until the border closes at 5:30 p.m. and heads home. The ride is bumpy. Only the roads that lead to the casinos are paved, the rest are rocky, dusty and torturous. Traffic is slow and can be spirit-breaking for travelers.

Wani's house is a long way from even the slums, in the middle of nowhere surrounded by tall grass and mud.

It was already dark when we reached her shack. Her mother, with a baby and two toddlers, was waiting for her. She gave her mother her day's earnings and started to care for the children, feeding them dinner. Everything leaked, the younger children were all naked and wet.

Wani didn't even have time to wipe her face before starting the housework. Sometimes the family eats, sometimes it doesn't. Her father did not come home that day -- she can never tell when he will. Her brother went to Thailand eight months ago and has not been heard from since.

Her friend next door was sold and taken to Thailand just a month ago. Young girls attract the best prices. Wani is an ordinary child in Poipet, and children like her are targets for traffickers.

But Wani is relatively lucky because she still lives at home.

Mwet, a 13-year-old girl, lives in the care of NGO Goutte Dfeau. She accepted a drink from a stranger a year ago in Poipet and blacked out. After waking up in Thailand, she was forced to sell candy and flowers in bars. Living with nine other children under the watch of an adult, she had to make 300 baht a day in order to be fed. Most of the time she went hungry.

She was afraid to discuss her experience, so I changed the subject and asked her about dreams she had had.

"Being whipped by electric wires." She said in a small voice. I asked her if it had actually happened, and she said, "He would whip me with electric wires when I could not make enough money. All over my body."

She tried to run away only to be caught, taken back and whipped. She tried to ask for help and failed. Finally, after five long months, she was lucky to be picked up by the police and sent back to Cambodia.

When she reached the border, she was malnourished and in shock. Her mother had died of AIDS and her father had left with another woman while she was away. Mwet now lives at the NGO's facility with her younger brother.

But at least Mwet has pleasant memories of her mother and believes she was loved.

Another girl, Sali, was sold twice by her mother -- each time for 1,000 baht. On the day I met her, she was preparing to go to see her mother the next day. The NGO Homeland can only take a child for a maximum of two years -- their ultimate aim is to return kids to the community, either to their own families or to foster homes.

Sali threw up that night, and was so sick she could not make the trip. However, she suddenly looked better when it was decided she could put the trip off to another day. I could not help but think she was afraid to see her mother again.

We went to see her anyway. She lived in Poipet, and had clean clothes -- a rarity. Her shack was small and she had two small children and a young male "cousin" living with her.

"The woman told me she could find work for Sali," she said, explaining why she sold Sali the first time. "The baby was sick and my husband had just left me. I had no choice."

Sali was sent back by authorities. "Sali said she lived in a house looking after small children and although she was beaten, she said it was OK," her mother said. "So I sent her out with the same woman again for another 1,000 baht."

Sali has four siblings.

"Two boys are with relatives," her mother said, when I asked about the others. I doubted it was true; they may well have shared the same fate as Sali.

"What if the baby gets sick again?" I asked her, "Will you sell Sali again?"

"No. Now that I know she was mistreated, I will never sell her again. I will let her look after the children and I will work to support her."

She confessed, however, that she owed 10,000 baht. Sali, 11, was very pretty and could sell for as much as 6,000 baht. I really didn't know whether it was a good idea to let Sali return to her mother.

Only 40 percent of Cambodia's population of 13 million are adults and the average household in Poipet has 5.7 children.

This makes the job of the trafficker easier. In addition, the porous border at Poipet means getting them over is simple.

We learned that a trafficker lived in the resettlement area and went to take a look. At first, no one was willing to talk to us. Finally, however, a young boy who had been sold and sent back over the border gave us directions to a house.

The shack looked ordinary from the outside. It turned out to be the house of a local policeman and his family. The wife came out to greet us and showed us inside. Immediately we could see it was far more luxurious than the other houses.

We asked if she knew of anyone involved in trafficking children. She said no. When we left, we took pictures of her and her neighbors. We decided to go back and ask the boy to look at the pictures.

"There she is!" he said pointing at the policeman's wife on the camera's screen.

I returned to find her chatting with people outside her house. I took her by the shoulders, "So it was you. Why?"

She was defiant and demanded to know who had told us about her. We quarreled as she continued to deny she was involved.

"I have nothing against people trying to get rich, but not at the expense of children," I nearly screamed at her.

People fled as the accusations flew and the truth seemed to come out. She did not fit my image of a trafficker -- she was young, beautiful and a mother herself.

But she was in a hurry to get a little richer, even if it meant harming innocent children.

"It would be difficult to prosecute with no witnesses," local people told us. "And since her husband is a policeman, it would be even harder."

The local UNICEF branch was informed, however, and they will be watching her.

UNICEF has launched a program for children in need of special care. The activities include reception teams at the border to receive deported children. In collaboration with NGOs and the Ministry of Social Affairs, there are now recovery centers -- half-day informal schools that provide trafficked children with meals, formal education in resettlement areas, and vocational training.

UNICEF also offers psychological assistance, community-based child protection projects, legal assistance and protection for children.

I visited a half-day school beside areas marked off as minefields. The rain left the road so muddy no one can walk in shoes. The only way was to walk barefoot.

About half of the 150 children sitting around eating their first meal of the day at 1 p.m. -- rice and bamboo shoot soup -- had been taken to Thailand. None of them wanted to go back, but all of them wanted to work -- to help their families by earning money.

Of the nearly 50,000 children in Poipet, only 13,000 go to school. Only 600 children reach sixth grade. If Wani had been to school, she would be a sixth grader now, but she only worries about being sold and sent to Thailand.

Child traffickers exploit the most beautiful things about children: innocence, obedience, their desire to help the family, and their vulnerability. As responsible global citizens we cannot let this continue.

The gap between rich and poor gives people with money the ability to buy anything. Including lives.

Children are not commodities. Lives cannot be sold. We must unite to decry this trade until nobody can ignore the facts. If we remain quiet, we are the silent partners of the traffickers. Let the children be heard through your voice.