£ódź - maybe because of a huge railway cargo terminal, £ódź Olechów - one of the biggests in Poland: goo.gl/maps/UNn2M
And because of a central location of £ódź in Poland.
A track gauge in Russia and in Poland is different (apart from one one-track cargo line in southern Poland, so called LHS, which lays hundreds of kilometers south from £ódź: en.wikipedia.org/wiki/PKP_rail_line_65). The train must change it on the Russia-Poland border. As far as I remember, in Russia it is 1520 mm, while in Poland (and in western Europe) 1435 mm.
Speaking about Polish-Russia border, I meant of course the border between Poland and countries of former Soviet Union, in this case probably Belarus. Sorry for this simplification.
And answering the question what is carried - I may mention this article: kurierkolejowy.eu/aktualnosci/18856/Pierwszy-pociag-z-Lodzi-do-Chin-ruszy-w-kwietniu.html
From Lodz freight trains will go to China. This means that not only from the Middle Kingdom to the boat, but also in the other direction will flow goods on rails. The first line to Chengdu will begin in April - reported "Journal of Lodz".
Will mainly drove foreign paper, but also razors, manufactured in Lodz. Transportation company realizes Hatrans of Lodz in cooperation with YHF Hatrans Chengdu Logistics.
In April last year, began to run trains between Chengdu in central China and Lodz. Currently, the road is forty-train on this route. By the end of last year to station Olechowo reached thirty-five warehouses in China. Carried the auto parts, textiles, electronics and advertising materials, and even shoes. About 80 percent of the goods is in Poland, and the rest are transported to Germany, France, the Czech Republic and Slovakia, and Hungary.
The number of trains from Chengdu China to Lodz this year will be higher, as they began to run from January, not April, as in 2013. In total, they have to be about 50.
In short - form £ódź to China: mainly paper from somewhere out of Poland and safety razors produced in £ódź (Gilette factory). From China to Poland - car parts, clothes, electronics, commercial materials and shoes. 80% of incoming goods stays in Poland, the other part goes mainly to Germany, France and Czech Republic, but also to Slovakia and Hungary.
And I don't suppose it to be able to change the economy of the £ódź region in the following years. Nowadays the city of £ódź suffers from big social problems caused by the collapse of the textille industry in 1990s, which dominated in this city (in fact, thanks to this industry the city appeared and grew up in 19. century). And being a terminal of one train from China, while still most of goods comes by sea, won't change it.
On the other hand even without this train from China the region of £ódź (especially the area nearby the Stryków town) is alredy becoming an important logistics centre due to the location in the centre of Poland, nearby the newly-built intersection of the main highways in Poland: north-south (A1) and west-east (A2).
Sorry for so many posts, but after some time I cannot edit the previous posts any more even if I come up with something more.